BACKGROUND: The Saudi Arabian Ministry of Health (MOH) controls the utilization of the free pharmacy benefit program (PBP) by having a closed universal formulary and ensures the effectiveness of the PBP by instituting a pharmacy & therapeutics (P&T) committee in each hospital. OBJECTIVES: To test the relationship among the levels of development P&T committees and patients' access rates to prescription drugs. METHODS: A cross-sectional descriptive survey design was conducted in the first phase and covered 127 MOH pharmacy managers at non-specialized hospitals. The survey gathered information about: hospital, pharmacy, and P&T committee characteristics. The survey results were used to classify the MOH hospitals according to the levels of development of the P&T committee. In the second phase, the prescription audit phase, hospitals deliberately were selected based on the hospitals' P&T committee levels of development. From each hospital, 150 patient records were systematically sampled and patient's access rate was calculated for each patient. Analysis of variance (ANOVA) was used to test the existence of a significant difference in the access rates across the levels of development of P&T committee. RESULTS: Of 127 MOH hospitals, 81 (63.7 %) hospitals were valid for the analysis. Of 81 hospitals, 13, 24, 39, 5 hospitals have undeveloped, poorly, partially, and developed P&T committees, respectively. A total of 6885 prescription drugs were prescribed for 2850 patients in 19 audited hospitals. The overall rate for patients' access was 97.3%. The ANOVA tests for the existence of a significant difference of access rates across the levels of development of P&T committee showed mixed results. CONCLUSIONS: The positive relationship between the levels of development of P&T committee and patient's access to prescription drugs was not conclusive. However, the finding might be due to lack of enough data and controls of other confounding variables rather than inexistence of the relationship.