BACKGROUND AND OBJECTIVE: The MAHLER survey examined the impact of the European guidelines for the treatment of chronic heart failure (CHF). Especially, the trial addressed the question whether adherence to treatment guidelines leads to a reduction in the rate of CHF and cardiovascular (CV) hospitalization. The present sub-study presents the Germany specific data of the MAHLER study and compares the results with the results in other European countries. PATIENTS AND METHOD: The gobal adherence index (GAI) shows the proportion of correctly prescribed heart failure medications per patient. Class adherence indicators for angiotensin-converting enzyme (AC)-inhibitors, beta-blockers, spironolactone, diuretics and cardiac glycosides and general adherence indicators (GAI3 adherence to first three classes of heart failure medications, GAI5 adherence to five classes) were constructed. In the German sub-study, 251 patient were included, who were seen by 21 cardiologists in private practice (mean age 68,6 + 10,4 years; 173 man, 78 woman; 158 NYHA II; 91 NYHA III, 2 NYHA IV). RESULTS: Mean adherence to CHF therapy guidelines was 63 % for GAI3, 62 % for GAI5. Compared to the other MAHLER-study countries, Germany was on place two and three concerning GAI3 and GAI5, respectively. Strong adherence to treatment guidelines in Germany led to a reduction of CHF and CV hospitalization rate by 40 % (p < 0.033). Thus, the German data confirm the results of the international study indicating that a good GAI3 performance is an independent predictor of time to hospitalization. Hitherto, the relative risk for hospitalization was higher for CHF patients in Germany than for patients in all other European countries. CONCLUSIONS: In Germany like in other European countries, guideline adherence for CHF therapy leads to a reduction in hospitalization rate.