Studies on agronomic performance and aerial dry matter (DM) partitioning for some important agronomic traits were undertaken from 10 mutants generated from microsperma and macrosperma lentils (Lens culinaris Medik) and their three parents. Three dwarf mutants were significantly (P ? 0.05) shorter in plant height under both the short-day and long-day conditions compared to the parental genotype PL 639. Consequently, these mutants produced lower yields than the parental genotype. Six mutants of macrosperma variety HPL 4 flowered significantly (P ? 0.05) earlier under both the daylengths, which was reflected by significant (P ? 0.05) increase in pods per plant, seeds per plant, and eventually seed yield per plant under both daylengths. All the dwarf microsperma mutants exhibited significantly (P ? 0.05) less contribution of aerial DM to pods and, hence, produced less yields than the parental genotype. However, macrosperma mutants significantly (P ? 0.05) increased the allocation of DM to pods at the expense of stem and branches under short-day and leaves under long-day photoperiod. Dwarf microsperma mutants may perform well under close densities while macrosperma mutants may be used directly or indirectly in a lentil improvement programme.