This is a two center pharmacokinetic and safety dosing study of IV gallium nitrate (Ganite®) in cystic fibrosis (CF) patients. Eighteen subjects are planned. Each subject will be administered a single 5-day infusion of study medication (one of 2 doses). No placebo is used. Each subject will receive 5 days of continuous infusion of the experimental treatment. There will be two dosing cohorts (cohort 1: 100 mg/m2/day and cohort 2: 200 mg/m2/day). Cohort 2 will begin enrollment only after Data Safety Monitoring Committee (DSMC) safety review and approval of cohort 1 data. Study visits occur at baseline (day 1), day 3 (visit 2), day 6 (visit 3), day 8 (visit 4), day 14 (visit 5), day 28 (visit 6), and day 56 (visit 7).