Aim. To field test a survey method for estimating the abundance of breeding Water Rail and to provide an assessment of coarse-scale habitat selection. Methods. Water Rails were surveyed in 1996–97 at 77 wetland sites across Wales using broadcast vocalizations from a handheld cassette player. Volunteers were recruited to allow maximum geographical coverage during the month-long survey period, generally making three early morning visits to each site. Basic habitat characteristics were recorded for all sites and more detailed information, including freshwater invertebrate samples, were taken from a subset of 22 sites. Results. A minimum of 43 to 49 breeding pairs of Water Rail were counted. Numbers of individuals differed significantly between the two survey years, but estimates of the number of pairs were consistent. Water Rail occurrence at a site was significantly related to the presence of wet reed Phragmites sp. Dry sites with low vegetation cover were the least occupied. Water Rail abundance was positively correlated with the abundance of Odonata, Plecoptera and Diptera larvae, but lack of data on actual dietary composition prohibits concluding a causal relationship. Conclusion. We hypothesize that increased Water Rail abundance associated with expanses of wet reed reflects a combination of nest safety, reduced risk of predation, and increased food availability. Current reed-bed management to maintain wetland conditions, often standard procedures for such systems, are probably beneficial to Water Rail. This work demonstrates that useful information on ecological preferences for otherwise secretive birds can be obtained from vocalization surveys.