Quality control in an andrology laboratory deals with multiple variables and complexities well beyond those in other laboratories. Therefore one of the most common reactions to demands for quality management in andrology is that 'quality' in assisted reproduction techniques (ARTs), especially in andrology, is not measurable. In spite of this reaction the following path must be adhered to in order to guarantee and improve quality in the andrology laboratory: after the term 'quality' is defined, criteria for quality must be set up and followed according to certain quality guidelines, which may originate from the literature or may be derived from the results and experiences within each laboratory. The implementation of working procedures according to the guidelines covers the activities in an andrology laboratory. The effectiveness of some of them is, however, evaluated differently and therefore they are discussed controversially. High-quality laboratory work is essential but what is actually done with the data received is of equal importance. It is the interface between quality control and quality assurance. The evaluation of results discovers the causes of problems, finds a way of correcting them, and anticipates future occurrences. A quality control programme must contain the handling of laboratory equipment as well as the preparation of media and, at first, the semen analysis which is performed either manually or automatically according to WHO criteria. Furthermore, it includes all common techniques of sperm preparation and, in addition, migration and survival tests for the determination of sperm function.