The incidence of abdominal aortic aneurysms (AAAs) has been reported to be increased in heterozygous (PiMZ) and homozygous (PiZZ) alpha 1-antitrypsin (alpha 1 AT) deficiency. We report a further case of AAA in a PiSZ alpha 1AT-deficient female with primary biliary cirrhosis (PBC). Moreover, to assess the risk of AAA in patients with PiZZ alpha 1AT deficiency, we conducted a retrospective study based on 30 consecutive autopsied adult cases of severe alpha 1AT deficiency identified during the period 1963-1993 in the city of Malmö, Sweden, during which autopsies were performed in 49,548, or 58.4%, of all residents in the city who died. From the homozygote frequency in the general population, 50 of these would be expected to have alpha 1AT deficiency. The disease had been diagnosed in 35, and autopsies had been performed in 30 adults. Each autopsied case was matched with four controls selected from the same autopsy register, and the Mantel-Haenszel odds ratio (ORmh) was calculated. We found one case of AAA amongst the 30 PiZZ individuals autopsied, and one case amongst 120 autopsied controls (ORmh = 2.65, 95% confidence limits, 0.47-15.0; P = 0.273). We found no significant evidence of the relationship between AAA and the PiZZ polymorphism, although previously reported by others. At least in severe alpha 1AT deficiency, any coexistence of the PiZZ phenotype and AAA would seem to be fortuitous.