Summary objective To compare the outcome of treatment of Sudanese kala-azar patients treated under field conditions with either branded sodium stibogluconate (SSG) (Pentostam GlaxoWellcome) or generic SSG (Albert David Ltd, Calcutta, supplied by International Dispensary Association, Amsterdam). method Randomised comparison. 271 patients were treated with Pentostam and 245 with generic SSG. results No statistically significant differences in cure rate or mortality were detected between Pentostam and generic SSG. No differences in side-effects between the two drugs were noted. The initial cure rate at the time of discharge was 93.7 and 97.6%, respectively; the death rate during treatment 5.9 and 2.4%. Six months follow up was achieved in 88.5% of the discharged patients. Two patients had died in the Pentostam group and two had died in the generic SSG group, giving a final death rate of 7.5 and 3.7%. The number of relapses in the Pentostam and generic SSG groups were 3 and 1, respectively. The final cure rates, calculated at 6 months after discharge, were 91.3% and 95.9%. conclusion No difference was observed in the performance of generic SSG compared to Pentostam for the treatment of visceral leishmaniasis in Sudan. Generic SSG can be routinely and safely used for the treatment of kala-azar. Generic SSG costs only 1/14 of the price of Pentostam. The use of generic SSG may make treatment of kala-azar affordable for national governments in Africa.