In industrialized countries, the initiation of antiretroviral therapy (ART) is based on virological, immunological and clinical markers. The objective of this study was to identify treatment gaps when ART initiation is based on clinical staging alone. The method employed was a retrospective study of 5784 patients enrolled in an HIV treatment programme in two urban and two rural sites in Ghana. Of the patients, 29.5% were in clinical Stages I and II and had a CD4+ T-lymphocyte count less than 200 cells/mm(3). Significantly more patients in clinical Stage I from urban sites (37.0%) had a CD4+ T-lymphocyte count less than 200 cells/mm(3) as compared with patients from rural sites (23.8%) (P value <0.05). In addition, more men (39.9%) in clinical Stage I had a CD4+ T-lymphocyte count less than 200 cells/mm(3) when compared with women (27.4%) (P value <0.05). In conclusion, clinical staging cannot identify a relatively large number of patients who need ART. A wider availability of CD4+ T-lymphocyte count testing will optimize the identification of patients eligible for ART.