Ambulatory rehabilitation concepts for women with psychosomatic disorders and with pre-school children are rare and moreover not yet assessed. An economic concept for the evaluation of indirect costs and (patient) time costs is being developed in this article and applied to an ongoing ambulatory rehabilitation programme for mothers at the Hanover Medical School. In health economic evaluations time cost is expressed by loss and reduction of working time, time for housework, and leisure time. These are indirect cost items (working time) and direct non-medical costs (housework and leisure time). To estimate the loss of working time (and hence production loss) the human capital approach and the frictional cost approach can be applied. Loss of time due to housework can be estimated either by the production of goods and services or by the opportunity costs of the equivalent working time. Loss of leisure time can be partial or total whereas a total loss and a loss of working time are considered to be analogous. The health economic evaluation of the ambulatory rehabilitation programme for mothers is designed as a randomised controlled study with repeated data collection. The parameters of indirect and direct non-medical costs are measured at the beginning of the rehabilitation programme and until twelve months later by means of questionnaires, face-to-face and telephone interviews. So far, results of the evaluation show that the actual time cost of the rehabilitation programme is DM 6,162 for each mother and the time cost because of the utilisation of the health care system is DM 996 per four weeks. Therefore, the patient costs are obviously higher than the direct medical costs for the programme which makes it clear that taking into account the costs of the patient (especially the time costs) can make a decisive difference in the evaluation of alternative treatment programmes and may possibly reverse the advantages of an alternative.