Though many studies on gene action of yield and yield related traits have been conducted on bambara groundnut, none of these focused on seed size and weight. Hence, this study was conducted to established inheritance pattern based on seed weight. Five bambara groundnut genotypes from Nigeria, namely Giwa, Duna, Cancaraki, Jatau, and Maiki were evaluated in randomized complete block design with three replication. The seeds of each genotype were grouped into three seed weight categories namely large, medium and small-seed size. Data were collected on 12 agromorphological traits and statistical analysis was conducted using SAS version 9.4 and variance component and heritability were estimated for each character. The present study revealed significant levels of variability among the five genotypes, fifteen combinations of seed size and genotypes, seed size categories and interaction of genotypes and seed size categories for most of the yield and yield components. High values of genotypic coefficient of variation (GCV) coupled with genetic advance (GA) were reported for the number of medium seed per plant, total large seed weight per plant, total medium seed weight per plant and hundred seeds weight, while moderate GCV was