Studies on the effects of guided imagery in patients with fibromyalgia show varying results. This randomized controlled trial (n = 65) aims to give more insight into the effects on pain, functional status, and self-efficacy. Daily pain was assessed with a pain diary using a Visual Analogue Scale. Functional status and self-efficacy were measured at pretest, posttest, and follow-up using the Fibromyalgia Impact Questionnaire and the Chronic Pain Self-Efficacy Scale. No effects of guided imagery could be established. Explanations for the diverging results between studies might be found in the content of the exercises, length of the intervention period, and background of participants.