Evaluation occurs in a context fraught with ethical issues. Evaluators are regularly faced with ethical tensions that are likely to influence the quality of their work. By developing an analytical model that categorizes evaluators along an altruistic-corporatist axis, we sought to understand which factors influence the ethical sensitivity of evaluators. To this end, utilizing a qualitative research design using vignettes, we exposed a dozen Canadian evaluators to ethically problematic situations to examine their ability to identify the ethical issues within the scenarios. The ensuing results allowed us to conclude that an evaluator's ethical sensitivity is partially explained by the altruistic or corporatist nature of that evaluator; it also depends on other factors such as knowledge of the prescriptive norms in ethical matters, experience conducting evaluations, and the milieu and the working conditions within which the evaluators operate.