Three annual forage legumes (Lablab purpureus, Vigna unguiculata and Vicia dasycarpa) were undersown at three different dates (10, 25 and 40 days after emergence of sorghum) on two spacing (every and every two rows of sorghum) to evaluate the effect of forage legumes, undersowing dates and row spacing on sorghum grain, DM stalk and DM forage yield. The trial was conducted at Sirinka and Chefa trial sites of northeastern Amhara region for two consecutive years (1999 and 2000). Among tested forage legumes, undersowing Vigna unguiculata and Vicia dasycarpa respectively, gave significantly (p0.01) highest grain yield of 29.2) and 61.8 q/ha, which were higher than sole sorghum grain yield by 13.6 and 4.5% at Sirinka and Chefa. Also significantly (p0.01) higher DM stalk yield of 8.1 and 7.3 t/ha were obtained from Vicia dasycarpa and Vigna unguiculata at Chefa respectively, which were lower by 0.8 and 10.5% than sole sorghum DM stalk yield. However, Lablab purpureus that gave significantly (p0.01) lower grain yield (23.7 and 53.6 q/ha) at Sirinka and Chefa respectively gave significantly (p0.01) higher DM forage yield of 3.0 and 1.2 t/ha. The interaction effect of forage legumes and date of undersowing had only shown significant (p0.01) effect on DM forage yield each location.