Today municipal biosolids are widely used for supplying crop nutrients thus permitting the recycling of essential plant nutrients otherwise wasted. Despite this, there are growing concerns over the continuous use of biosolids, among which nitrate and heavy metal toxicities are at the forefront. One winter wheat field experiment was established at the Stillwater Agronomy Research Station (Oklahoma State University, Stillwater, OK) in the fall of 1993. The objective of the study was to assess the effect of long-term application of biosolids and ammonium nitrate fertilizer on wheat grain yield, N uptake and, grain metal concentrations. Six N rates (0, 45, 90, 180, 270 and 540 kg N ha-1 yr-1) and two N sources (ammonium nitrate, 34-0-0 and anaerobically-digested biosolids) were evaluated. Two additional treatments included lime applied to the high N rate plots (540 kg N ha-1 yr-1). The experimental design was a randomized complete block with three replications. Measurements were taken on grain yield, N, Pb, Zn and Cd concentrations in grain, and soil pH. Analysis of variance was performed on all measurements. Unequally spaced orthogonal polynomial contrasts were fitted to the N rates separately for each N source. Preplanned single degree of freedom non-orthogonal contrasts were also used to detect differences in treatments. This report includes data for 2001-2004 only. All biosolids and ammonium nitrate treatments gave higher yields than the controls. Biosolids did not give higher grain yield and N uptake than the ammonium nitrate fertilizer. The 4-yr data also showed that the metals evaluated were not found at concentration of concern to human and animal health or the environment. At least from this long-term study it would be plausible to conclude that when applied at the agronomic rates, biosolids can be continuously applied to a continuous winter wheat production with very low risk.