A study was conducted to evaluate the effects of plant spacing and N fertilizer application on dry matter yield and chemical composition of Urochloa hybrid cv. Mulato II grass for the first 150 days after planting. A factorial experiment with 3 urea fertilizer levels (0, 50 and 100 kg/ha) and 4 spacings between plants and rows (20 × 20, 30 × 40, 40 × 60 and 50 × 80 cm) with 3 replications was used. Data collected were dry matter yield (DMY), leaf:stem ratio and chemical analyses, i.e. crude protein (CP), ash, neutral detergent fiber (NDF), acid detergent fiber (ADF) and acid detergent lignin (ADL) concentrations. Results indicated that DMY, leaf:stem ratio, CP%, NDF% and ADF% were significantly (P<0.05) affected by interactions between plant spacing and fertilizer level. However, ash and ADL were significantly (P<0.05) affected only by main effects. The highest DMYs (9.18 t/ha and 8.93 t/ha) were recorded for narrowest plant spacing (20 × 20 cm) with higher urea fertilizer level (100 kg/ha) and narrowest plant spacing (20 × 20 cm) with medium urea fertilizer level (50 kg/ha), respectively. CP% ranged from 14.6 to 20% and leaf:stem ratio from 1.12 to 1.82:1. Similar studies need to be conducted over longer periods to determine to what extent these findings relate to performance over the life of a permanent pasture.