Rectus abdominis (RA) diastasis is a risk factor for abdominal muscle dysfunction and reduced quality of life postpartum. It is thought that supplementary abdominal supports might reduce the diastasis. However, there is limited research assessing the efficacy of abdominal supports/binding.To determine the effects of Tubigrip and a rigid abdominal belt in reducing RA diastasis in the first eight weeks postpartum.Randomised clinical trial.62 women undertook ultrasound imaging to measure their RA diastasis prior to and after an eight week intervention wearing either Tubigrip or a rigid abdominal belt. Data analyses involved repeated measures ANOVA and correlational methods.The RA diastasis reduced by 46% from a mean 4.6 cm-2.5 cm over the eight week intervention period with no significant difference (p > 0.05) across groups. Women wore the Tubigrip for a significantly (p < 0.05) longer number of hours (Median: 278) compared to those in the belt group (Median: 81 h). The length of time that women wore Tubigrip or the belt was not associated with the percentage reduction in the RA diastasis (p > 0.05). There was no significant difference in the diastasis across vaginal and Caesarean section deliveries at baseline. There was a significant difference (p < 0.05) in the percent reduction of the RA diastasis across deliveries post-intervention (vaginal delivery mean: 48% vs C-section: 40%).There was no difference across groups post-intervention in the RA diastasis, and it is questionable whether either support improves upon that associated with natural healing alone.