Objectives To determine the rate and nature of complaints and the outcomes of the complaint management at a large heart centre in Tehran.

Design A retrospective review of all verbal and written complaints recorded over 30 months.

Setting A large heart centre in Tehran, Iran.

Population All 312 105 admissions (47 041 inpatients, 138 842 outpatients and 126 222 ambulatory services) between July 2005 and January 2007 at Tehran Heart Centre, during which the hospital received 1642 verbal and written complaints.

Main outcome measures Proportion of admissions with verbal and written complaints, type of complaints and outcomes of the complaint management.

Results A total of 1642 (5.2 per 1000) complaints were received, of which 1457 (4.64 per 1000) were verbal, and 185 (0.56 per 1000) were in written format. 34.7% of the complaints were related to admission procedures, followed by 34.1% communication, 13.8% waiting time, 6.8% delay and 4.1% ignoring the standards of clinical care. Over 90% of complaints were resolved by explanation or verbal apology, 2.1% of them led to a change in the process or procedure, and 4.8% were deemed disapproved claims.

Conclusions The majority of patient complaints in Tehran Heart Centre are related to admission procedures or communication; most of them are verbal and resolved in the early stage as an explanation or apology. The hospital complaint management system has the potential to resolve the majority of such complaints in an early stage.