The park was expected to draw large crowds when it opened on February 8, 2001.
There were four districts with 22 shows and attractions and 15 restaurants.

On January 14, a Los Angeles Times article titled "The most Jam-Packed Theme Park on Earth?"
stated, "Senior Disney officials acknowledge that there will be days when California Adventure will have to turn patrons away, particularly in the first weeks after the park opens, during spring break and again in the summer."
However, the actual attendance that year was substantially less than expected.
This is suggested to have happened as a result of negative reviews from early visitors, including the lack of focus in the Hollywood Pictures Backlot, the lack of attractions for children, a large number of off-the-shelf attractions, a high number of stores and restaurants relative to the number of attractions, and having a theme that was considered to be redundant, given that the park is located in California.
The park also lacks a perimeter berm to separate it from surrounding neighborhoods.
The berm in Disneyland Park uses trees and earthen mounds to establish a physical barrier around the park so that structures external to the park cannot be seen, with the aim of more fully immersing guests in the park setting.
At Disney California Adventure Park, nearby hotels, power lines, radio towers, and the Anaheim Convention Center are all visible, reducing the sense of immersion.
 Furthermore, Disney had originally planned the park to be aimed at adults, rather than children, which became the basis of significant criticism.

The park opened to only 5 million visitors in 2001 while its sister park Disneyland saw 12.3 million visitors during the same time frame.
Low attendance caused Disney to lower ticket prices for California Adventure, slashing as much as $10 off the park's ticket prices.
In its first year, the park only averaged 5,000 to 9,000 visitors on weekdays and 10,000 to 15,000 on the weekends, despite having a capacity of 33,000.
Visitor surveys reported that only 20% of visitors to the park in its first year were satisfied with their experience.
By October 2001, both Wolfgang Puck and Robert Mondavi had closed their high-profile restaurants in the park, citing low crowds, though Mondavi remained as a sponsor.

In the 2019 documentary series The Imagineering Story, Walt Disney Imagineer Kevin Rafferty described how he and fellow imagineers felt about the original design of California Adventure: 
Much to our chagrin, it didn't adhere to our fundamental design principles of theme park design.
There were all these visual cues that were kind of contradictory.
There were great big California letters.
There was a stylized Golden Gate Bridge that was kind of foreshortened and was kind of fake and suggested that this wasn't a real place, and the super graphics on the toy store.
And the first statement that you saw when you walked into the gate with the sharp sun.
And you know, frankly, you could have seen that at a shopping mall in Newport Beach.
It's like 'why is it here?'
The park was expected to draw large crowds when it opened on February 8, 2001. There were four districts with 22 shows and attractions and 15 restaurants.
On January 14, a Los Angeles Times article titled "The most Jam-Packed Theme Park on Earth?" stated, "Senior Disney officials acknowledge that there will be days when California Adventure will have to turn patrons away, particularly in the first weeks after the park opens, during spring break and again in the summer." However, the actual attendance that year was substantially less than expected. This is suggested to have happened as a result of negative reviews from early visitors, including the lack of focus in the Hollywood Pictures Backlot, the lack of attractions for children, a large number of off-the-shelf attractions, a high number of stores and restaurants relative to the number of attractions, and having a theme that was considered to be redundant, given that the park is located in California. The park also lacks a perimeter berm to separate it from surrounding neighborhoods. The berm in Disneyland Park uses trees and earthen mounds to establish a physical barrier around the park so that structures external to the park cannot be seen, with the aim of more fully immersing guests in the park setting. At Disney California Adventure Park, nearby hotels, power lines, radio towers, and the Anaheim Convention Center are all visible, reducing the sense of immersion.  Furthermore, Disney had originally planned the park to be aimed at adults, rather than children, which became the basis of significant criticism.
The park opened to only 5 million visitors in 2001 while its sister park Disneyland saw 12.3 million visitors during the same time frame. Low attendance caused Disney to lower ticket prices for California Adventure, slashing as much as $10 off the park's ticket prices. In its first year, the park only averaged 5,000 to 9,000 visitors on weekdays and 10,000 to 15,000 on the weekends, despite having a capacity of 33,000. Visitor surveys reported that only 20% of visitors to the park in its first year were satisfied with their experience. By October 2001, both Wolfgang Puck and Robert Mondavi had closed their high-profile restaurants in the park, citing low crowds, though Mondavi remained as a sponsor.
In the 2019 documentary series The Imagineering Story, Walt Disney Imagineer Kevin Rafferty described how he and fellow imagineers felt about the original design of California Adventure: 
Much to our chagrin, it didn't adhere to our fundamental design principles of theme park design. There were all these visual cues that were kind of contradictory. There were great big California letters. There was a stylized Golden Gate Bridge that was kind of foreshortened and was kind of fake and suggested that this wasn't a real place, and the super graphics on the toy store. And the first statement that you saw when you walked into the gate with the sharp sun. And you know, frankly, you could have seen that at a shopping mall in Newport Beach. It's like 'why is it here?'
Disney California Adventure