The use of inorganic nitrogen (N) fertilizers in grasslands is likely to increase as restrictions on manure applications are implemented. Concerns have been raised about the economic and environmental impact of N loss from these fertilizers through ammonia  volatilization. This study evaluated ammonia volatilization losses from urea, urea ammonium nitrate (UAN) and urea-polymer (UP) applied to grazed, tall fescue (Festuca arundinacea sp) pastures at 50 kg N/ha in fall and spring of two years. Fertilizers were applied in triplicate circular plots (30-m diameter) and ammonia loss was measured by the modified passive flux method for up to 60 days following application. In some cases urea lost significantly more (p<0.05) ammonia than UAN and UP, while in other cases there were not any significant differences among treatments. A separate plot study was conducted in fall and spring to evaluate tall fescue N uptake from UAN, UP, and ammonium nitrate.  In general, UAN and UP were about 60% as effective as ammonium nitrate, in partly due to ammonia volatilization losses.