Principle goals of sedation for eye surgery are to provide patient comfort and to allow the patient to stay calm during both retrobulbar injection and surgery. Insufficient sedation may not prevent the patient from moving during retrobulbar injection, whereas very deep sedation may result in respiratory complications during surgery. The aim of the present study was to evaluate the effectiveness and suitability of a combination of diazepam and propofol for sedation for both application of retrobulbar block and subsequent elective eye surgery. One-hundred and fifty patients were randomly allocated to receive either diazepam, propofol or a combination of both drugs before retrobulbar injection. Tolerance of retrobulbar injection and comfort during the surgical procedure were assessed by comfort scores using a nominal analogue scale between 1 (worst possible condition) and 6 (best conceivable condition). Side effects related to sedation were recorded. The combination of diazepam and propofol resulted in the highest comfort scores for both retrobulbar block (5.3 +/- 0.3) and the surgical procedure (5.4 +/- 0.4). Diazepam alone did not produce adequate sedation for retrobulbar block (3.1 +/- 0.3), whereas comfort scores during surgery were significantly higher (5.3 +/- 0.3) compared to propofol alone (3.6 +/- 0.4). No severe side effects induced by sedation were noted in any of the study groups. The combination of diazepam and propofol proved able to provide a reliable degree of sedation with minimal side effects for both retrobulbar block and surgery. The combination was clearly superior to the sedation induced by propofol or diazepam alone.