Aim: To determine the rate of development of ocular disease in patients presenting with mucous membrane pemphigoid (MMP) involving their oral mucosa. Methods: Diagnosis of oral MMP was made on the basis of clinical signs,histology, and direct and indirect immunofluorescence. Age, race, sex, age at diagnosis, progression of eye signs, duration of follow up, and time to progression of ocular disease were recorded. Results: 30 patients with established oral MMP were reviewed. The mean age at diagnosis was 65.2 years (range 46-84 years) and 16/30 (53%) were male. At initial ocular review nine (30%) patients showed ocular signs of pemphigoid, of whom two had mild (IIA IIIB), four moderate (IIB IIIC), and three severe (IIC IIID) disease. The mean interval between diagnosis of oral MMP and first ophthalmic review was 19.3 months (range 0-144). Over the period of follow up two (7%) patients developed ocular disease at 19 months and 48 months, respectively, despite having had no evidence of ocular involvement at presentation. In total, 11 (37%) patients with oral disease eventually showed ocular disease with a calculated incidence rate for the development of ocular disease of 0.03 per person year over 5 years. Conclusions: MMP may affect different tissues at different stages, often separated by many years. Patients with MMP involving their oral mucosa are at significant risk of developing ocular disease and should remain under ophthalmic review. Aim: To determine the rate of development of ocular disease in patients presenting with mucous membrane pemphigoid (MMP) involving their oral mucosa. Methods: Diagnosis of oral MMP was made on the basis of clinical signs, histology, and direct and indirect immunofluorescence. Age , race, sex, age at diagnosis, progression of eye signs, duration of follow up, and time to progression of ocular disease were recorded. Results: 30 patients with established oral MMP were reviewed. The mean age at diagnosis was 65.2 years (range Atopic ocular signs nine (30%) patients showed ocular signs of pemphigoid, of whom two had mild (IIA IIIB), four moderate (IIB IIIC), and The mean interval between diagnosis of oral MMP and first ophthalmic review was 19.3 months (range 0-144). Over the period of follow up two (7%) patients developed ocular disease at 19 months and 48 months, respectively, despite having had no evidence of ocu lar involvement at presentation. In total, 11 (37%) patients with oral disease culled from ocular disease with a rate of incidence of for development of ocular disease of 0.03 per person year over 5 years. Conclusions: MMP may affect different tissues at different stages, often separated by many years. Patients with MMP involving oral mucosa are at a significant risk of developing ocular disease and should remain under ophthalmic review.