The perinatal mortality rate (PNMR) is a key health status indicator. It is multifactorial in aetiology and is significantly influenced by the quality of health care. While there is an ethical imperative to act to improve quality of care when deficiencies are apparent, the lack of controls - when an intervention is applied to an entire service - makes it difficult to infer a causal relationship between the intervention and any subsequent change in PNMR. However, by specifically measuring avoidable perinatal deaths (those due to error or omission on the part of the health service), this limitation is partially overcome, and the impact of the intervention can be more rigorously evaluated. This paper reports the impact of perinatal audit in a rural African health district between 1991 and 1995. A total of 21,112 consecutive births were studied: the average number of deliveries increased by 31% from 325 to 424 per month. The PNMR (birth weight ≤ 1000 g) in 1991 was 27/1000, increased to 42/1000 in 1992, and fell steadily to 26/1000 in 1995 (40% reduction; p = 0.002). The proportion of avoidable deaths fell from 19% in 1991 to zero in the second half of 1995 (p = 0.0008). While factors associated with perinatal mortality are many, complex, and interrelated, this report suggests that mortality can be reduced significantly in resource-poor settings by improving quality of health care. Including the measurement of avoidable deaths in perinatal audit allows the impact of interventions to be more rigorously assessed than by simply measuring the PNMR.