Quality of health performance is of increasing international importance. The potential value of the implementation of a guideline-based medication assessment tool (MAT) has been evaluated in order to measure and improve adherence to guideline recommendations in secondary prevention of coronary heart disease (CHD). An existing MAT developed in the UK based on internationally recognised clinical evidence has been further developed [with criteria extended to secondary prevention of CHD only] for application in Norway. Content validity was demonstrated using a two round Delphi process among an expert group (12 reviewers, consensus threshold 75%). Inter- and intra-observer reliability testing was conducted with agreement expressed by Cohen's kappa (κ). The designed MAT was applied in a pilot study and application time was measured to inform clinical utility of the tool in real world settings. A total of 85 patients (69% male) undergoing coronary angiography were included. Mean age was 65.4 years (SD 11.6). The new MAT is named MAT-CHDSP and comprises 21 review criteria. Consensus among the expert group (n = 12) was obtained for all final criteria. Reliability testing showed κ in the range (0.79-0.90). Applicability in the pilot study was 63% (n = 1106) and adherence was 65%, 95% CI (64-66) (n = 791). The mean application time for the experienced user was 1.5 minutes (SD 0.3). MAT methodology might merge the increasing demand for continuous assessment of quality of health performance with the clinical pharmacist's need for a standardised and explicit working tool.