A study was conducted in 1998 with four determinate potato cultivars at Alemaya University, Ethiopia, to determine the effects of flowering and fruiting on tuber yield and quality of potato. Fruiting (control), flowering, and non-flowering and non-fruiting plants were evaluated in a split-plot design with three replications. Removing flowers and fruits increased total tuber yield by 2.2% and 17%, respectively, compared to the control indicating that reproductive growth had a depressing effect on tuber development. Similarly, flower and fruit removal significantly increased specific gravity and dry matter (DM) per cent of tubers and may be due to the elimination of assimilate diversion to reproductive growth. Significant difference in specific gravity and per cent DM was exhibited among varieties. A highly significant positive correlation (r = 0.99**) was observed between specific gravity and per cent DM indicating that specific gravity is an excellent measure of DM content of potato tubers.