Nitrogen is the most important and widely applied nutrient in sweet pepper production as it improves vegetative growth as well as fruit production. Therefore, the present research was aimed to evaluate promising sweet pepper cultivars as a function of different nitrogen fertilizer levels for semi-arid conditions of Pakistan during 2018 and 2019. Four nitrogen levels (75, 100, 125 and 150 kgha−1) and three sweet pepper cultivars (Ganga, Winner and Savio) were adopted in this study. Vegetative growth as well yield attributes were found highest during the cropping season of 2019 as compared with 2018. Plant height, stem diameter, canopy diameter, fresh and dry biomass of sweet pepper enhanced by the increased application of nitrogen from 75 to 125 kgha−1. All the yield contributing traits including number of fruits per plant, fruit fresh weight per plant and fruit yield per hectare were found the highest with nitrogen application of 150 kgha−1. In most of the crop traits, application of 125 kg Nha−1 and 150 kg Nha−1 produced statistically similar results. Cultivars respond differently to the nitrogen application. Ganga and Savio behaved similarly in response to nitrogen application. They had a quadratic response to nitrogen application; maximum growth and yield were at 125 kg Nha−1 and then decreased at 150 kg Nha−1. In contrast, Winner showed a somewhat linear response to nitrogen application and maximum growth, biomass and yield were recorded at 150 kg Nha−1. Planting a pepper cultivar with improved nitrogen use efficiency can result in maximum yield in a semi-arid region.