HIV treatment guidelines state that patients' readiness should be assessed before initiating highly active antiretroviral therapy (HAART) to assure adherence. None of the guidelines provide a way to measure readiness. Therefore, this article sought to review the literature on readiness to determine if there was a viable predictor of adherence. Twenty-seven articles were reviewed. Nine described studies that examined the relationship between a measure of readiness and HAART adherence. No readiness measure demonstrated clinical utility as a predictor of adherence. Study flaws included small sample sizes (only one study >100 patients), short follow-up periods (all ≤1 year and six were ≤5 months, four ≤1 month), measures of readiness that related poorly to adherence, and inconsistent adherence measures (eight different measures were used by the researchers). Neither the guidelines nor the literature will help clinicians judge who should initiate HAART and who should delay treatment.