OBJECTIVE Despite evidence supporting antiretroviral therapy (ART) in recent HIV infection, little is known about factors that are associated with successful ART. We assessed demographic, virologic, and immunologic parameters to identify predictors of virologic response. METHODS A 24-week observational study of ART on persons enrolled within 6 months of their estimated date of infection (EDI) evaluated baseline demographics and the collection of blood and gut specimens. METHODS Flow cytometry analyses of blood and gut lymphocytes allowed characterization of CD4 and CD8 T cells at study entry and end. Additional assessments included soluble CD14 (sCD14), lipopolysaccharide, CD4 T-cell counts, and HIV RNA levels. RESULTS Twenty-nine participants initiated ART, and 17 achieved undetectable HIV RNA by study end. A longer time from EDI to ART, older age, higher sCD14, lower proportions of central memory CD4 T cells, and higher proportions of activated CD8 T cells were associated with detectable viremia. Multivariable logistic regression found only older age and elevated sCD14 were independently associated with persistent viremia. Additionally, we observed that ART in recent infection did not result in discernible recovery of CD4 T cells in the gut. CONCLUSIONS In persons who started ART within 3-33 weeks from EDI, age and microbial translocation were associated with detectable HIV RNA. As observed in other cohorts, ART in recent infection did not improve proportions of total CD4 T cells in gut-associated lymphoid tissue (GALT). This lends support to further evaluate the use of more potent ART or regimens that protect the GALT in recent HIV infection.