This greenhouse study tested the effect of smoke-water and the smoke-isolated biologically active compound karrikinolide (KAR1) on growth and photosynthetic pigments of Jatropha curcas L. seedlings. Fifteen-day-old seedlings were sprayed once weekly for 5 weeks with three dilutions of smoke-water (1 : 250, 1 : 500, and 1 : 1000 v/v) or KAR1 (10–7, 10–8, and 10–9 M). Growth parameters and photosynthetic pigment concentrations of 75-d-old seedlings were measured. Foliar application of both smoke-water and KAR1 on J. curcas seedlings showed significant increases in stem width, shoot length, chlorophyll a, chlorophyll b, total chlorophyll, and total carotenoid concentrations compared to the untreated control. KAR1 significantly improved leaf area, shoot and root dry mass, seedling-vigor index, and photosynthetic pigments as compared to control treatments. These results suggest the possible use of smoke-water and KAR1 to achieve a vigorous and well established crop of J. curcas.