The major aim of this experimental study was to determine whether the characteristics of absorption or worry would moderate the effects of progressive muscle relaxation (PMR) or guided imagery delivered to groups. Twenty male and 49 female students were administered either PMR or imagery by a certified hypnotherapist. Although both treatments produced significant increases in relaxation and reductions in stress and anxiety (p = .000), evidence of absorption or worry moderating these effects was not found. However, 5 cases of paradoxical anxiety enhancement were observed with imagery, but not PMR. In these cases, instead of relaxation scores increasing from pretest to posttest and stress and anxiety decreasing, the opposite occurred. A one tailed Fisher's exact test confirmed this relaxation-induced anxiety was significant (p = .048). It is suggested that PMR may hold certain inherent benefits over imagery when delivered to groups, as it may be less likely to cause adverse effects.