Although Mexico has a well-established legal framework regulating fisheries for the green abalone Haliotis fulgens and pink abalone H. corrugata, there is empirical evidence about a sizeable abalone black market and substantial sectors of fishing communities dedicated to poaching. An investigation was conducted about abalone poaching in a bay located off the Baja California Peninsula, Mexico. The main objective was to determine how poaching is perceived by abalone fishermen, particularly the attitudes of legal and illegal fishing groups and the factors that determine their perception of poaching. Abalone fishermen’s perceptions and attitudes about poaching seem to be conditioned by a small number of factors that were identified through a discriminant analysis (e.g., deep-seated practices and knowledge about abalone fisheries; between-group violence; and the likelihood that a given poaching work day will fail due to capture by authorities, confrontation by legal fishermen, or insufficient abalone harvest). This investigation provides an indirect exploration of the abalone poaching phenomenon and the factors underlying this practice. © 2009 Taylor and Francis Group, LLC.