Neem (Azadirachta indica A.) tree has been known to be useful in soil enrichment and for insect, pest and disease control. Thus, it is of benefit to study the allelopathic efficacy of powdered neem seed cake on the germination and seedling growth vigour of cowpea, groundnut, sesame, soya beans and Bambara groundnut. A field research work was conducted at college of Agriculture, Hassan Usman Katsina Polytechnic during the 2008 raining season using split plot design with three replication and six main plot treatment 0, 0.5, 1, 2, 4, and 8 tons/ha and the tested seeds as main subplot treatments. The result showed that powdered neem seed cake was found to have no allelopathic effect on the germination of cowpea, sesame, Bambara ground nut, ground nut at 0-2 tons/ha and soya beans at 0-4 tons/ha and have no allelopathic effect on the seedling growth vigour of cowpea, sesame, soya beans, Bambara ground nut and ground nut at 0-4 tons/ha. Further research is required on the allelopathic effect of powdered neem seed cake on the germination, growth and yield of these tested crops.