Lost productivity accounts for a significant proportion of the total cost of alcohol. This study quantifies the costs associated with alcohol consumption using survey data collected from four alcohol surveys conducted in Auckland between November 1990 to May 1992. The total sample size was 4662, of which 2638 were drinkers in paid employment. A computer-assisted telephone interviewing system was used to interview a random sample that closely matched the Auckland population. Respondents gave information about their typical alcohol consumption and frequency of absences from paid employment which were a result of their drinking. They also gave a report of the number of times in the past 12 months when they felt their work had been impaired as a result of their drinking. The cost of absenteeism was recorded as the number of times a respondent reported time away from work multiplied by gross income. Estimates of reduced work efficiency were derived from US figures, which estimated a 25% reduction in work performance among heavy alcohol users; 3.7% of the sample reported alcohol-related absences and 12% reported reduced efficiency days. There was a significant difference in both the number and cost of absentee and reduced efficiency days reported between the top 10% and the bottom 10% drinkers. A conservative estimate of alcohol-related lost productivity among the working population of New Zealand (with a population of 3.4 million and a per capita absolute alcohol consumption of 9.7 litres) was found to be $57 million per year.