On August 4, 1904, approximately 420 square decametres (10 acres) of the town burned; 130 buildings were destroyed, including the town hall, the school, the church and 77 barns.
One person was killed and 706 left homeless.
The losses were assessed at 1,392,696 Reichsmarks.
The fire was caused by a portable stove that children were using to bake apples and that tipped over.
Firefighting efforts were considerably hindered by the different hose couplings used by Württemberg firefighting units.
The fire shocked the whole of Germany; during the following days King William II visited the town, as did more than 40,000 of the curious.

By August 8, the Württemberg Ministerial Division of Road and Water Construction had organized a rebuilding committee led by Oberbaurat Richard Leibbrand, which began by erecting a temporary barracks encampment to house the homeless over the winter.
A new town plan was then drawn up: when the town was rebuilt, the main street (still the center of the town and called König-Wilhelm-Straße since 1906) was widened by 11 metres (36 ft) by not rebuilding on the slope leading up to the church and instead supporting the hillside with a retaining wall, the Planmauer, which was extended by about 100 metres (330 ft).
The major public buildings (town hall, church, school, teacher's and minister's residences, and the Dorastift kindergarten) were designed by the architects Paul Schmohl and Georg Stähelin in a traditional Swabian style with Jugendstil elements.
By 1906, rebuilding was largely complete.

Ilsfeld remained primarily rural in character until World War II; industry failed to gain a foothold, primarily  because of a lack of infrastructure.
In 1935 there were 335 agricultural concerns, mainly smallholdings, employing 40–60% of the residents, and 120 small businesses with a total of 220 employees.
A planned post bus connection to Lauffen am Neckar, which would have enabled residents to work at the cement works, failed to materialize in 1929.
On August 4, 1904, approximately 420 square decametres (10 acres) of the town burned; 130 buildings were destroyed, including the town hall, the school, the church and 77 barns. One person was killed and 706 left homeless. The losses were assessed at 1,392,696 Reichsmarks. The fire was caused by a portable stove that children were using to bake apples and that tipped over. Firefighting efforts were considerably hindered by the different hose couplings used by Württemberg firefighting units. The fire shocked the whole of Germany; during the following days King William II visited the town, as did more than 40,000 of the curious.
By August 8, the Württemberg Ministerial Division of Road and Water Construction had organized a rebuilding committee led by Oberbaurat Richard Leibbrand, which began by erecting a temporary barracks encampment to house the homeless over the winter. A new town plan was then drawn up: when the town was rebuilt, the main street (still the center of the town and called König-Wilhelm-Straße since 1906) was widened by 11 metres (36 ft) by not rebuilding on the slope leading up to the church and instead supporting the hillside with a retaining wall, the Planmauer, which was extended by about 100 metres (330 ft). The major public buildings (town hall, church, school, teacher's and minister's residences, and the Dorastift kindergarten) were designed by the architects Paul Schmohl and Georg Stähelin in a traditional Swabian style with Jugendstil elements. By 1906, rebuilding was largely complete.
Ilsfeld remained primarily rural in character until World War II; industry failed to gain a foothold, primarily  because of a lack of infrastructure. In 1935 there were 335 agricultural concerns, mainly smallholdings, employing 40–60% of the residents, and 120 small businesses with a total of 220 employees. A planned post bus connection to Lauffen am Neckar, which would have enabled residents to work at the cement works, failed to materialize in 1929.
Ilsfeld