Specimens of urine and blood were collected from as many members as possible of a community living in an area of urinary schistosomiasis in The Gambia. The light infections found in many of the subjects appeared to have little or no effect of haemoglobin levels, but some of the intense infections were associated with reduced haemoglobin levels. Significant differences in haemoglobin levels between ova-positive and ova-negative subjects were apparent only in males aged from 15 to 44 years, and significant differences in the prevalence of anaemia between groups with different egg counts were apparent only in children aged from five to seven years and from eight to 14 years.