BACKGROUND: Malignant melanoma of the choroid is the most common ocular primary malignancy, but is still a rare tumour. The occurrence of bilateral uveal melanoma is exceedingly rare. The probability of any one individual developing bilateral melanoma is estimated to be 1 to 50 million. MATERIALS AND METHODS: A retrospective search of the photo database of patients between 1970 and 2006 with uveal melanoma was performed. RESULTS: Four patients with bilateral melanoma were identified. The case reports of the two females and two males are presented. CONCLUSIONS: In summary, bilateral primary uveal melanoma seems to occur more frequently than expected. The estimated probability for patients with unilateral primary uveal melanoma of developing bilateral melanoma is 0.2 %. In single cases the interval between the occurrence of the second melanoma can be more than 30 years. In patients with a history of malignant melanoma of the choroid it is important to carefully observe the other eye life-long.
