Abstract Potato yield is strongly dependent on nitrogen fertilization, thus understanding the crop ecophysiological response is essential to improve the management of the agro-ecological resources. However, studies on biomass and nitrogen partitioning under different nitrogen fertilization are still limited for potato cultivars of the tropical Andes of Venezuela. The aim of this study was to determine the effects of nitrogen fertilization on patterns of biomass and nitrogen partitioning during the main phenologycal stages of cultivar Granola in Mérida, State of Mérida, Venezuela. The fertilization treatments (partitioning) were: Control treatment (0-N), 133 kg N ha-1 (133-N), and 400 kg N ha-1 (400-N). Experimental plots were set up in a randomized blocks design with three replications. Biomass and nitrogen levels were measured for each organ of the plant during the main phenological stages of the crop. The tuber yield performance and the total biomass were strongly influenced by nitrogen availability and the assimilatory biomass. Total biomass production as well as biomass and nitrogen partitioning to each plant organ followed the sequence fertilization rates: 400-N > 133-N > 0-N. However, biomass and nitrogen partitioning to the roots and stolons was higher in the treatment with limited nitrogen levels. Proportional changes among aboveground and belowground biomass are adaptive responses to nitrogen deficit; which in turn, are determining factors in crop production.