Colorectal cancers are rare in developing countries, but are the second most frequent malignancy in the affluent world. Data on colorectal cancer in HIV-positive patients are limited. Up to now, there are no published data on treatment patterns, response to therapy, or survival in this setting. Oxaliplatin is an antineoplastic agent currently indicated, concomitantly to fluorouracil and leucovorin, for the treatment of advanced colorectal cancer. The FOLFOX-4 regimen (oxaliplatin 85 mg/m(2) as a two-hour infusion on day 1; leucovorin 200 mg/m(2) as a two-hour infusion on days 1 and 2, fluorouracil as a bolus infusion on days 1 and 2, followed by a fluorouracil 22-hour infusion 600 mg/m(2) for two consecutive days every two weeks), with concomitant highly active antiretroviral therapy (HAART) is feasible and active, while the HIV infection is not a limiting factor for its use. Moreover, the concomitant use of HAART does not seem to increase the toxicity of the FOLFOX-4 regimen.