Interactions between HIV and surgical diseases are relatively poorly described in high HIV prevalence settings. We report HIV prevalence and its associations in a prospective study of adults admitted to surgical units in Soweto, South Africa. Voluntary counselling and testing (VCT) for HIV was offered to surgical inpatients. Research nurses interviewed participants at enrolment and doctors reviewed records after discharge. In HIV-infected participants, CD4 counts and viral loads were ascertained. Of 1000 participants, 537 consented to VCT, of whom 176 (32.8%, 95% CI 28.8-36.9%) tested HIV positive. A history of tuberculosis (adjusted odds ratio (AOR) 3.0, 95% CI 1.5-6.2) or sexually transmitted infection (AOR 2.7, 95% CI 1.8-4.2) was associated with HIV infection. Diagnoses of cutaneous abscesses (OR 3.4, 95% CI 1.4-8.1) and anorectal sepsis (OR 3.1, 95% CI 1.1-9.0) were associated with HIV and indicated advanced disease. There were no differences in rates of operative procedures, wound sepsis, investigations or length of stay by HIV status. Hospital-acquired pneumonia was more common in HIV-infected participants (P=0.028). In conclusion, in this high HIV prevalence setting, resource utilisation is similar between HIV-infected and uninfected patients in surgical wards where high rates of HIV in young adults support routine HIV testing. WHO clinical staging of HIV should include anal sepsis as an indicator of advanced HIV disease.