The objective was to compare long-term outcomes following outpatient microwave endometrial ablation in the postmenstrual phase with those following day surgery microwave endometrial ablation after standard drug-based endometrial preparation. Of the women originally recruited, 154/197 (78%) returned questionnaires. The primary outcome of satisfaction was high in both groups (71% postmenses versus 65% preparation) as were the amenorrhoea rates (84% versus 87%). There was no significant difference in the hysterectomy rates between the two arms. It can be concluded that microwave endometrial ablation outcomes are not affected in the long term by undertaking the procedure in the postmenstrual phase in an outpatient setting.