Seventeen colorectal cancer patients received as first (12 cases) or second line (5 cases) treatment a combined chronotherapy with CPT 11 (infused at day 1 from 2 to 8 am; peak at 5 am), given with 5 FU (700 mg/m2 per day ; days 2-5) and folinic acid (300 mg/m2 per day, days 2-5) both infused from 10 pm to 10 am with a peak at 4 am, and carboplatin (40 mg/m3/day - days 2-5 ; infused from 10 am to 10 pm - peak at 4 pm). The doses of CPT 11 could be easily increased from 120 up to 180 mg/m2 in successive cohorts of four patients through acceptable toxicity. Thus, five patients have already been treated in the phase II part of the trial. An interesting tumoral outcome has been observed: 88% major responses with no progression; median time to progression: nine months and median survival: 19.7 months.