In Germany the in-hospital rehabilitation of patients with cardiac diseases is standard. Especially because of criticism of effectiveness and wasting of resources we evaluated in a pilot study a rehabilitation program with an in-hospital start, followed facultatively on ambulatory basis at the same institution, at the cardiac rehabilitation clinic. The aims of the study were to find out the acceptance of the the program by the patients, the safety and the impact of the: facultative ambulatory rehabilitation program on cardiovascular risk factors. From January 1993 to December 1995 the primary enclosing criteria (cardiac disease suitable for rehabilitation, age < 70 years, lodging < 40 km) were fulfilled by 612 patients, 122 female. 268 (43.8%) were disclosed on medical grounds because of the rigid pilot character of the study, for 74 (12.1%) patients was the participation on organisational grounds not possible. Sixty-six of the remaining 270 patients prefered the facultative continuation of the rehabilitation on ambulatory basis for 1 or 2 weeks, the entire rehabilitation. lasting up to 3 weeks. During the ambulatory phase the patients slept at home, otherwise these patients followed the same procedure as the in-hospital participants, Despite of severe medical concerns 3 further patients wished to participate on facultative ambulatory continuation of the rehabilitation, among these were 2 women, only 5 of the total 70 patients of the facultative ambulatory program group being female. There were no significant differences among 24 patients with CAD of both groups during the rehabilitation and in a control after 14.8 months (Table 3). The impact on serum total cholesterol and LDL cholesterol was positive (Table 2), albeit after 14.8 months no more significant. Over the control period there were a negative development of serum triglyceride level and significant negative effects On the body weight. There were no complications among the 66 patients during the facultative ambulatory phase of the rehabilitation, in contrast to those 37 of 268 patients who had to be disclosed because of medical concerns (Table 1). During the rehabilitation the drug therapy was optimized for many participants The control after 14.8 months revealed that these remedies were followed with great accuracy by the physicians at home (Figure 1). In conclusion, a cardiac rehabilitation program with an in hospital start of:! weeks, going over to ambulatory rehabilitation for 1 to 2 weeks, is as effective and safe as an in-hospital cardiac rehabilitation. As known, amelioration of the long term results has vet to be achieved.