Abstract: Background and Objective: Lettuce is one of the very important cash and food vegetable crops. Lettuce is more susceptible to nutrient deficiencies than most crop plants because of their shallow root system. Therefore, this study was initiated to assess the response of lettuce to farm yard manure and nitrogen fertilizer application rate on its growth and yield. Materials and Methods: The current study was conducted at Debre Markos, North West Ethiopia, during 2018, under irrigation the study consists of three levels of Farm Yard Manure (0, 15 and 30 t ha–1) and three levels of nitrogen (0, 75 and 150 kg Nitrogen ha–1). The experiment was conducted in 3×3 factorial arrangements in a randomized complete block design with three replications. Data on growth and yield, parameters were recorded and analyzed using SAS Computer Software version 9.2. Results revealed that interaction of FYM and N fertilizer significantly (p<0.05) influenced. Results: The results showed significant variation was obtained from fertilizers tested with regard to plant height (cm), leaf number, root length (cm) Leaf Width (cm) and Total Yield (t ha–1). The highest plant height 25.79 cm and 25.08 cm was obtained from application of 75 kg N h–1 and 30 t ha–1 Farm yard manure, respectively lowest plant height was obtained from application of 0 kg N ha–1 and 0 t h–1 farm Yard Manure. Maximum (32.66) number of leaves per plant was noticed from application of 75 kg Nitrogen ha–1 with 30 t ha–1 farm yard, which was on par with application of 150 kg ha–1 Nitrogen with 30 t ha–1 farm yard (29.55). The lowest number of leaves (21) per plant was obtained from application of 0 kg Nitrogen with 0 t farm yard manure. the tallest root length of lettuce (13.44 cm) was obtained from 15 kg ha–1 farm yard manure and 75 kg ha–1 Nitrogen. Conclusion: The highest yield of lettuce (31.34 t ha–1) was obtained when the plots received combined application of 75 kg ha–1 of N and 30 t ha–1 of FYM. Therefore, the present study suggested that lettuce grown with 30 t ha–1 farm yard manure and 75 kg ha–1 nitrogen showed better growth and yield.