The germination of Sesbania sesban seeds was studied under controlled environmental conditions. Interactive effects of temperature and light, effects of salinity and effects of different pre-treatments of seeds were studied. Sesbania seeds were placed in Petri dishes with filtration paper and the germination and radical development followed during seven day periods. The seeds generally germinated within one or two days. There was no difference in percent germination between dark and light treatments, but the development of radical length was significantly influenced by both light conditions and temperature. Germination was highest at 30 and 37°C (up to 85%) but seeds also germinated readily at 22°C. No germination was observed at low (5 and 13°C) and high (45°C) temperatures. Salinities up to 100 mM NaCl (5.8 ppt) did not influence the germination percentage, but at 200 and 250 mM germination was reduced to 29 and 17% respectively. Pre-treatment of seeds in hot water, sulphuric acid or calcium sulphate had only minor effect on germination rate. The results are consistent with S. sesban being an opportunistic tropical wetland species capable of establishing itself in a wide range of environmental conditions.