Capture-recapture analysis is an analytical tool being used in epidemiological research to estimate incidence rates for missing cases and unreliable reporting. Its contribution to batterer program evaluations is examined through a capture-recapture analysis of a multisite evaluation of batterer programs (n = 853). Capture-recapture analysis is applied to various subsamples of the multisite study and to different outcomes (i.e., any reassault, "severe" reassault) to explore the utility of capture-recapture. Finally, the capture-recapture estimates are compared to only the women's reports and to adjusted women's reports (women's reports supplemented with arrest records and men's reports), which are the basis of existing batterer program evaluation. The capture-recapture reassault estimate for the 15-month follow-up is equal to the adjusted women's reports (39%), but is 7% greater than the women reports. The subsample estimates for the individual sites appear to vary as a result of unreliable or unavailable arrest records.