ObjectiveLower availability of medicines in Nigerian public health facilities—the most affordable option for the masses—undermines global health reforms to improve access to health for all, especially the chronically ill and poor. Thus, a sizeable proportion of healthcare users, irrespective of purchasing power, buy medicines at higher costs from for-profit pharmacies. We examined user evaluation of medicine availability in public facilities and how this influences their choice of where to buy medicines in selected states—Cross River, Enugu and Oyo—in Nigeria.MethodsWe approached and interviewed 1711 healthcare users using a semi-structured, interviewer-administered questionnaire as they exited for-profit pharmacies after purchasing medicines. This ensured that both clients who had presented at health facilities (private/public) and those who did not were included. Information was collected on why respondents could not buy medicines at the hospitals they attended, their views of medicine availability and whether their choice of where to buy medicines is influenced by non-availability.Principal FindingsRespondents’ mean age was 37.7±14.4 years; 52% were males, 59% were married, 82% earned ≥NGN18, 000 (US$57.19) per month, and 72% were not insured. Majority (66%) had prescriptions; of this, 70% were from public facilities. Eighteen percent of all respondents indicated that all their medicines were usually available at the public facilities, most (29%), some (44%) and not always available (10%). Reasons for using for-profit pharmacies included: health workers attitudes (43%), referral by providers (43%); inadequate money to purchase all prescribed drugs (42%) and cumbersome processes for obtaining medicines.ConclusionsLower availability of medicines has serious implications for healthcare behavior, especially because of poverty. It is crucial for government to fulfill its mandate of equitable access to care for all by making medicines available and cheap through reviving and sustaining the drug revolving fund scheme and encouraging the prescription of generic drugs in all public health facilities.