In this study, the effect of a mental training programme on several psychological variables and field hockey performance (penalty stroke) was evaluated. Twenty-nine female hockey players, playing at subnational level, were divided into an experimental, a placebo-control and a control group. Subjects in the experimental group received instruction on how to relax, concentrate and imagine making penalty-strokes. In addition, they received an audio tape containing these mental training instructions, and were asked to listen to it every day for about 10 minutes over a period of seven weeks. The hockey performance of the experimental group was significantly better on the third test occasion than that of both control groups. Competitive state anxiety prior to performing penalty strokes did not differ between the three groups. However, at the end of the experiment, the experimental group reported feeling more confident, more relaxed and better concentrated when making penalty strokes than subjects in either placeho-control or control group. Subjects in the experimental group attributed their feelings to listening to the audio tapes.