Symbiotic performance of three genotypes of lentil (Lens culinaris Medik) was compared with and without inoculation of different strains of R. leguminosarum bv. viciae for three consecutive years under field conditions. All the three genotypes produced comparable number and dry weight of nodules in two out of the three years. Genotype LL 147 was found superior to PL-4 and PL 639 by producing significantly more grain yield dUring 1996/97 and 1997/98 and mean grain yield in the different years. Inoculation with different R. leguminosarum bv. viciae strains significantly increased the number of nodules ranging from 19.3 to 41.4% and nodule dry weight from 28.6 to 63.6% in the different years. Irrespective of genotypes, strain LB-4 produced the highest number and dry weight of nodules in the different years. All the inoculated strains increased the grain yield significantly in the different years. The increase in mean grain yield with different strains ranged from 14.7 to 19.5%. Strain LB4 recorded the highest mean grain yield. Though interactions between genotypes and inoculated R. Ieguminosarum bv. viciae strains were not significant, nevertheless PL-4 and LL 147 genotypes responded better to LB-4 and LLR-22 strains, respectively in terms of nodulation and grain yield in comparison to the other strains.