Health workers who work with people who inject drugs may believe that their colleagues hold less favorable attitudes toward health services for people who inject drugs than themselves—a phenomenon termed pluralistic ignorance. This research explores whether the presumed attitudes of their colleagues, rather than their own attitudes, predict the behavioral intentions of health workers toward people who inject drugs. A total of 57 hospital-based health workers were surveyed to assess their attitudes toward harm reduction services for people who inject drugs and their perceptions of colleagues’ attitudes. They then responded to a scenario assessing their likelihood of prescribing opiate-based medication to people who inject drugs. Data illustrate that participants support harm reduction services for people who inject drugs more than they believe their colleagues do, demonstrating pluralistic ignorance. Interestingly, participants’ prescription of opiate-based pain medication was predicted by beliefs about their colleagues’ support for services for people who inject drugs, rather than their own beliefs.