Factors involved in promoting caulogenesis from hypocotyl explants of Phyllanthus fraternus were studied. Hypocotyl explants were cultured on B5 medium supplemented with 2,4-D or NAA in the presence and absence of BAP (at concentrations 0, 10(-7), 10(-6) and 10(-5)M). Adventitious shoots differentiated from callus developed from the cut ends of 12.5% of the hypocotyl segments cultured on medium supplemented with 10(-6)M BAP in combination with 10(-6)M 2,4-D or 10(-6)M NAA. Profuse rooting occurred from the hypocotyl explants on medium supplemented with 10(-6)M BAP + 10(-6)M NAA. Incorporation of casein hydrolysate in B5 medium along with 10(-6)M BAP + 10(-7)M 2,4-D enhanced the frequency of cultures with adventitious shoots upto 68.0%. Glutamine, glutamic acid or proline could partially substitute for the effect of casein hydrolysate. Amongst the hypocotyls from 3-14 d old seedlings, the best caulogenesis was obtained with hypocotyls from 7 d old seedlings both in presence or absence of casein hydrolysate. Best rooting of shoots was achieved on half-strength B5 medium supplemented with 10(-6)M IBA. After hardening, plantlets were successfully transferred to the soil.