A comparison was carried out of the psychological effects of a moderate aerobic training programme (n = 24) and an attention-placebo strength and flexibility training programme (n = 23) in previously inactive anxious adults from the general population. Training consisted of one supervised and three unsupervised sessions per week for 10 weeks. Effects were assessed with the Profile of Mood States, the State-Trait Anxiety Inventory and questionnaires indexing perceived coping ability. Seven participants dropped out of each condition during the training period. Expectations of benefit assessed pre-training, and satisfaction assessed post-training, did not differ between conditions. The moderate exercise programme led to significant improvements in aerobic fitness, and was associated with significantly greater reductions in tension-anxiety, depression and other moods than the attention-placebo condition, together with increases in perceived ability to cope with stress. Psychological responses were not correlated with changes in fitness assessed with bicycle ergometry or the 12 min walk/run test. These effects were maintained on 3 month follow up.