Women with diabetes often experience a higher level of anxiety. The aim of the study was to evaluate the effect of acupressure on relieving anxiety of women with gestational diabetes mellitus (GDM). A randomized clinical trial was conducted on 60 women with GDM at a university hospital. The participants were allocated to an experimental and a placebo group (30 women per group). The experimental group received a nurse-provided acupressure at the true point, and the placebo group received pressure (touching) at a sham (false) point. Anxiety was measured immediately in the groups prior to and after a 2-day intervention by a questionnaire and the Visual Analogue Scale. The data were analyzed using descriptive and inferential statistics. Results indicated that the acupressure group had significantly lower anxiety than the placebo group (p ≤ .0001). In conclusion, the effects of acupressure appeared to be effective in reducing anxiety in diabetic pregnant women.