Background: During the last 30 years there has been a proliferation of research into the menstrual cycle with particular focus on pre-menstrual syndrome (PMS). The research, however, has not specifically addressed the experiences of women with learning disabilities with regards to the menstrual cycle. The extent to which their experiences resemble those of non-disabled women is therefore not known. Aims: The research aimed to compare menstrual cycle change in women with learning disabilities with those of a group of non-disabled women. A further aim was to explore the subjective experiences of women with learning disabilities and to relate the findings to the research evidence pertaining to non-disabled women. Design: The study was cross sectional and employed both within and between groups comparisons. There were two parts to research and both quantitative and qualitative methods were used. Method: Quantitative: 34 women with learning disabilities and 50 non-disabled women completed a modified form of the Menstrual Distress Questionnaire (MDQ) regarding changes experienced across the menstrual cycle. Qualitative: A semi-structured interview was used to explore the views of eleven women with learning disabilities towards the menstrual cycle in general and menstruation in particular. Results: Both groups reported significant changes in mood and behaviour occurring across the menstrual cycle. Between group analysis revealed that control group reported significantly more change in the pre-menstrual phase of the cycle whereas the client group reported more change during menstruation. Analysis of the interviews indicated that women with learning disabilities have little knowledge of the menstrual cycle and experience menstruation as a debilitating condition. Conclusion: The focus on PMS in menstrual cycle research does not address the concerns of women with learning disabilities who appear to experience more difficulty with menstruation. The clinical and service implications are discussed and directions for future research suggested.