An experiment was conducted during summer season of 1993 and 1994 to study the effects of sowing date, irrigation and spacing on nodulation, dry-matter production and yield of summer groundnut (Arachis hypogaea L.), at Kalyani. Sowing on 15 February recorded significantly highest number of nodules/plant, dry weight of nodules and dry weight of pods/plant and pod yield than that on 15 January. Irrigation had no significant effect on nodulation. Two irrigations given at first phase of flowering and pod initiation recorded higher shoot and pod dry weight/plant than 1 irrigation. Three irrigations resulted in highest pod yield (2, 420 kg/ha) and moisture stress at pod-development stage and both at pod initiation and development stages reduced pod yield by 13.4 and 44.2 % respectively. The crop sown at 25 cm x 12 cm spacing recorded the highest nodules/plant, shoot dry weight and pod yield.