The effects of group gymnastics on neck pain were studied among 44 women in a printing company. A randomized cross-over design was used with two groups matched according to the work task, frequency of symptoms, and age. The treatment consisted of gymnastics for 45 min once a week for 10 weeks. Neck pain was rated by visual analogue scale and pressure pain sensitivity of the neck muscles was measured with an algometer. The results showed no clear effects of the group gymnastics program. An equal and significant reduction in pain ratings was seen in both groups after the first intervention in the spring. Recurrence of symptoms was seen in both groups in September, and no significant reduction in pain occurred during the second intervention in the autumn. The results suggest a seasonal variation in neck symptoms which has to be considered when planning or evaluating intervention studies.