Coronary heart disease (CHD) patients are currently attended by many different medical specialities. CHD patients must achieve the highest grade of treatment implementation and risk factors control. The aims were to describe differences in medical treatment of CHD according to the medical specialities. For this purpose we conducted an observational, cross-sectional, and multicenter study of CHD patients attended by internal medicine (IM), outpatient clinic cardiologist (OCC), hospital cardiologist (HC), and general practitioners (PC). Burden of noncardiac diseases was evaluated by the Charlson index. Joint prescription of antiplatelets, statins, beta-blockade agents and blockade of the renin-angiotensin system by angiotensin-converting enzyme inhibitors (ACEI) or angiotensin receptors blockers (ARB) was considered optimal medical treatment (OMT). A total of 2987 patients, mean age 67.4 (11.5) years and 71.5% males, were analyzed. Patients visited by IM physicians had slightly higher mean age and higher prevalence of hypertension, diabetes, and noncardiac diseases (median Charlson index 3.0, 1.0-5.0, vs. 2.0, 1.0-4.0, of total sample). OMT was prescribed in 25.9% (95% CI 25.6-26.2) of the patients and was statistically more frequently carried out by HC (32.1%) and OCC (29.0%) compared to IM (22.0%) and PC practitioners (21.5%). Multivariate analysis showed an independent association between OMT prescription and HC (OR 1.42; 95% CI 1.08-1.87) or OCC (OR 1.31; 95% CI 1.04-1.67); this association remained after including the Charlson index. Noncardiac diseases are the main clinical differences in CHD patients visited by different medical specialist although it does not explain the higher prescription of OMT by cardiologist.