To test the feasibility of rest first-pass radionuclide angiocardiography (FPRNA) using a 370-MBq (10-mCi) bolus and a single-crystal gamma camera, 40 patients underwent both FPRNA and equilibrium radionuclide angiocardiography (ERNA). Ejection fraction (EF) and regional wall motion (RWM) were assessed by three observers. The interobserver reproducibility was good: the intraclass correlation coefficient was 0.97 for both techniques. The correlation coefficient between FPRNA and ERNA EFs ranged between 0.90 and 0.92. FPRN EFs were significantly higher (P < 0.003) by less than 5 percentage points, this difference having no clinical implications for patient classification. The study provides arguments as to why this difference may be explained self-attenuation rather than counts statistics problems. Both techniques were concordant for RWM analysis. We conclude that FPRNA with 10 mCi is a reliable tool to assess rest left ventricular function, which makes it possible to perform simultaneously myocardial perfusion and function assessment in a single-day protocol using a single-crystal gamma camera.