Background Around 20–30% of alcohol use in low and middle-income countries is estimated to come from unrecorded sources, but little is known about the characteristics of its consumers. The aim of this study was to obtain information about users of unrecorded alcohol and describe factors associated with its frequent use. Method A cross-sectional study, using Respondent Driven Sampling (RDS), was conducted in Rio de Janeiro, Brazil in 2010. Individuals aged 18–65 who reported binge drinking in the last 12 months were recruited to participate in a structured interview. Three sources of unrecorded alcohol use were assessed: home-made/unrecorded; perfumes/lotions; and “medicinal” products (compounds made of herbs and local spirits). Results 343 individuals were recruited and 303 were interviewed. The sample comprised mostly of men (n = 256) from low socioeconomic strata, with a mean age of 38.8 (±12). Most individuals (71.8%) reported to have used more than one variety of unrecorded alcohol, which was found to be associated with: being older than 31 (OR 2.21; CI 95% 1.05–4.80), an AUDIT score >20 (OR 11.21; CI 95% 4.56–30.96), having used crack/cocaine (OR 2.29; CI 95% 1.02–5.21), and having received treatment for alcohol addiction in the last 12 months (OR 3.64; CI 95% 1.25–13.49). Conclusion Most unrecorded alcohol users were disadvantaged polysubstance users. Assessing unrecorded alcohol use has important clinical implications and should be screened for among crack/powder cocaine and alcohol-dependent patients.