The present investigation was carried out at Baramoon Research Station, Mansoura, Dakahlia Governorate, Egypt (+ 7m altitude, 30^o 11^- latitude and 28^o 26^- longitude), during Nili seasons of 2007/08 and 2008/09, to study the effect of slow release-N (urea formaldehyde "UF"; Sulfur coated urea "SCU", and compost) as compared with soluble-N (ammonium nitrate "AN") fertilizer on productivity, and quality of potato cv. Cara.The most important finding could be summarized as follows:         Compost _{9 ton fed}^-1plus SCU3 _{67.5 kg N fed}^-1 led to significant increase in all vegetative growth parameters of potato plants (plant height, leaf area/plant and dry weight/plant) in both seasons.         Significant differences were detected in total tuber yield and yield components among various treatments in both seasons. Compost _{9 ton fed}^-1 + SCU3 _{67.5 kg N fed}^-1andSCU1 _{135 kg N fed}^-1had significant effect in this respect.         Application of Compost _{9 ton fed}^-1 + SCU3 _{67.5 kg N fed}^-1 significantly increased tuber dry matter (in both season), starch and specific gravity of tuber (1^st season, only) and significantly decreased nitrate and nitrite content of tuber (both season), in comparison with other treatments.         The NPK % of potato tubers in treatment amended with Compost _{9 ton fed}^-1 + SCU3 _{67.5 kg N fed}^-1 was higher than with other treatments in two seasons. On the other hand, the greatest value of nitrogen use efficiency (NUE) was obtained by the application of SCU1 followed by UF2.         The highest net return was obtained from potato receiving Compost _{9 ton fed}^-1 + SCU3 _{67.5 kg N fed}^-1 in comparison with other treatments. Generally, it could be concluded that, application of nitrogen fertilizer in the form of Compost at the rate of 9 ton fed^-1+ SCU3 (67.5 kg N fed^-1) in potato fields was the most effective treatment for satisfactory improvements in productivity and quality yields with keeping the health and safety of human and environment.