OBJECTIVES: To determine differences in compliance of amlodipin and atorvastatin, and their combination either in 2-pill or single-pill forms. METHODS: Patient’s data about amlodipin and/or atorvastatin treatment were obtained from a Health Insurance Company over an 18 month period (January 2006 to July 2007). The indirect measure of compliance was based on the tablet count derived from the size and number of packages dispensed during a 200 days review period. The analyzed sample involved patients using only atorvastatin (7074), amlodipin (8177), a 2-pill amlodipin and atorvastatin combination (953) and amlodipin/atorvastatin in a single-pill (262). Compliance was measured as the percentage of days covered by a given drug. The compliance of patients using both drugs concomitantly was calculated as a product of the compliances of both drugs. We assumed one tablet as a daily dose for both substances. RESULTS: The mean compliance for patients using atorvastatin was 83.3% (SD 20.29), amlodipine 85.8% (SD 18.99). In patients using both drugs in 2-pills, compliance was 74.8% (SD 24.37), and in the group using amlodipin and atorvastatin in one tablet the compliance was 84.3% (SD 20.54) (p<0.001). Age was one of the relevant factors affecting compliance in all medications. CONCLUSIONS: Patients using both, amlodipine and atorvastatin, in a single-pill can reach higher compliance compared to patients using both of substances concomitantly. The results of the Czech pilot project on adherence are consistent with published literature.