Pathological lesions of the middle cerebellar peduncle include tumours, arteriovenous malformations, cavernous angiomas and spontaneous haematomas. Because of the very low incidence of these lesions, surgical approaches to the middle cerebellar peduncle are not commonly known. The authors decided to present their own experience based on five cases operated on at the authors' institution.Five patients were operated on, four with tumours and one with spontaneous haematoma of the middle cerebellar peduncle. In three patients the cerebellomedullary fissure approach was used, in one patient the paramedian supracerebellar approach, and in one patient the retrosigmoid approach.In all cases neoplastic lesions and haematoma were totally removed. In each case, balance disturbances and ataxia of extremities increased or occurred as a new sign. These disturbances diminished within several weeks after the procedure. In the case of location of the lesion also in the lateral part of the pons, the authors observed peripheral paresis of the seventh cranial nerve and paresis of the sixth cranial nerve, which tended to resolve.Pathological lesions of the middle cerebellar peduncle can be effectively treated surgically. The cerebellomedullary fissure approach has been found to be the best because it provides greater access to the dorsal surface of the middle cerebellar peduncle and to the lateral part of the pons. The most frequent complications of the procedure were instability and ataxia as well as paresis of the sixth and seventh cranial nerve when the lesion was found in the lateral part of the pons.