Abstract: A study was conducted to determine the effect of combined application of inorganic nitrogen and organic phosphorus fertilizers on growth of young tea plant (Camellia sinensis var. assamica). The field experiment was conducted in Gera district in Southwest (SW) Ethiopia during 2010/2011 and 2011/2012 cropping seasons. We used two fertilizers “Orga” and urea as sources of phosphorus and nitrogen, respectively. We tested four rates of nitrogen (75, 150, 225 and 300 kg N ha-1) combined with a constant rate of phosphorus (30 kg P ha-1) and one unfertilized control treatment. The experiment was laid down in a randomized complete block design with three replications. The results showed that combined application of inorganic nitrogen (urea) and organic P (Orga) significantly (p<0.01) enhanced plant height, number of leaves per plant, number of branches per plant, root length, leaf fresh and dry weight and root fresh and dry weight. Among the tested rates, combined application of 150 kg ha-1 N and 30 kg ha-1 P increased leaf number, plant height and branch number per plant by 164.3, 68.8 and 83.4%, respectively compared to control treatment. In conclusion, the use of inorganic nitrogen (urea) fertilizer at 150 kg N ha-1 combined with 30 kg P ha-1 (Orga) gave the best result in all assessed yield components variables and could be recommended for the study area for high yield and quality tea cultivation.