Abstract: The erratic nature of rainfall in the Kenyan semi arid highland regions, such as Naivasha, coupled with the high dependency on maize grain, usually results in relatively low and unstable yields. Chickpea is mainly cultivated as a rain-fed crop and water stress often affects both productivity and yield stability. Potential seed yield has been reported not to exceed 1.5 t ha ¹ in other countries but information on optimum nitrogen and Plant Population Density (PPD) has not been developed for Naivasha region. Therefore, A desi chickpea variety ICCV 97105 was grown in two seasons at NAHRC, KARI (Naivasha). Viz., February 27th-June 24 and June 30th to Oct 26th of 2005; in a RCBD with 4 levels of nitrogen (0; 20; 40 and 60 kg N ¹) and 4 planting densities (i.e., 74,074; 89,889; 111,111 and 148,148 seeds ha ¹). Maximum above ground biomass obtained was 5.06 and 4.37 tones ha ¹ for the first and second seasons, respectively. Application of 60 kg N ¹ produced 62 and 68% more biomass (DM) than the no N application treatment. The curvilinear response of above ground biomass to added levels of N with high coefficients of 0.944 and 0.989 in respective seasons signifies the possibility of increasing further chickpea biomass. Maximum grain yields were 2.57 and 1. 66 t ha ¹ in season I and II, respectively, a difference of 54.8%. This was attributed to the higher rainfall of 235 mm received in Season I as compared to 176.8 for season II, a difference of 76.2 mm water. The response of above ground biomass and grain yield to increasing PPD was found to be linear with very high regression coefficients of over 0.993 in both seasons. This revealed the strong dependency of chickpea grain yields on PPD. Harvest Indices (HI) ranged between 0.42 and 0.72. Application of 20 kg N ¹ produced a HI of about 0.6 and 0.5, in seasons I and II, respectively. Increase in planting population up to approximately 105,000 plants ha ¹ was observed to increase the harvest index of chickpea to over 0.6 and 0.41 in seasons I and II, respectively. Further increase in plant density beyond 110,000 plants ha ¹, however caused a decline in the rate of increase in HI of chickpea. Chickpea can be successfully grown in Naivasha during February to June and June to October seasons. Further research work is however, recommended with the aim of determining chickpea productivity under higher PPD, various watering regimes and agro-ecological environments.