Although use of cyclodiene organochlorine insecticides were restricted during the 1970's, avian mortality associated with them persists. From 1986 through 1990, we documented 122 cases of avian mortality caused by poisoning with chlordane and/or dieldrin in urban and suburban sites in New York, Maryland, and New Jersey. Eleven species of songbirds and 9 species of raptors were represented in these diagnoses. In a summer survey of songbird mortality in suburban neighborhoods, poisoning with cyclodienes accounted for 17% of the mortality. Composite samples of surface soils (top 5 cm) from lawns (20-50 lawns/composite) in 7 residential areas where poisoned birds were found contained 0.55-9.85 ppm total cyclodienes (dry basis). Limited collection (9 samples) and analysis of live adult Japanese beetles (Popilla japonica) contained up to 2.1 ppm dieldrin and 15.6 ppm chlordane-related compounds (wet basis). These data, plus accounts of cyclodiene use in the literature, led us to conclude that excessive use of cyclodienes on turf, prompted by the emergence of cyclodiene-resistant scarab beetle populations in the late 1960's and 1970's, was probably sufficient to account for most of the poisonings we documented in this and a previous report. Determination of organochlorine pesticide levels in turf soils should be completed before plans to enhance avian habitat are implemented in sites where scarab beetle control may have been practiced prior to the 1980's.