Introduction. Iris melanocytoma (IM) is a rare benign tumor, but unavoidable in differential diagnosis of pigmented iris lesions. According to the best knowledge of the authors it is for the first time in Serbia that a well-documented case of IM is presented and that the problem of this tumor is discussed. Case Outline. In the left eye of a 47-year-old white female at the iris in a six o?clock position, a highly pigmented, dome shaped lesion with a crater-like cavity in the center and with feathery margins was noticed. There were no signs of infiltration of surrounding tissue or intrinsic vessels and the lens was clear. Visual acuity and intraocular pressure were normal. An ultrasound biomicroscopy (UBM) revealed a well-defined lesion with high internal reflectivity, with a base diameter of 1.25 mm and a thickness of 0.80 mm in the periphery, and 0.53 mm in the central part. The diagnosis of IM of the left eye was established and regular checkups were performed for ten years. No changes in clinical or UBM presentation were established. Conclusion. Awareness of clinical presentation of IM is most important for correct diagnosis. Ultrasound biomicroscopy is a useful diagnostic procedure in the following up of IM.