Out of 84 patients with colchicine poisoning hospitalised between 1966 and 1976, 11 died during the first 72 hours. Amongst the 73 survivors, 20 showed signs of marrow aplasia between the 3rd and 6th days, lasting on average 4 days. The average amount of colchicine ingested by these patients was 0.5 to 0.8mg/5g. Marrow aplasia was associated with: -- infectious episodes in all cases, -- haemorrhage in 50%, -- dilution hyponatraemia in 25% (but in 50 % of patients if those in renal failure are excluded), -- regressive polyneuropathy in 10 % of cases, -- secondary alopoecia in all cases, -- weight loss of more than 10 % of initial weight in 60 %. Two patients died as a result of septicaemia. This mortality rate of 10 per cent despite the brief duration of the aplasia and the absence of underlying haematological disease would appear to be related to the susceptibility of these poisoned patients to endogenous secondary infections, essentially intestinal in origin.