Anecdotal accounts suggest some patients have experienced negative outcomes as a result of receiving genetics services from non-genetics providers, but empirical evidence of these incidents and their outcomes is limited. This study examined genetic counselors' perceptions of the occurrence of such incidents in the state of Minnesota. Twenty-five genetic counselors completed an on-line survey and 20 also participated in a semi-structured telephone interview. The interviewees recalled and described 37 specific incidents they perceived as having negative outcomes for patients and/or their families. Inductive and cross-case analysis revealed common themes including: adverse psychosocial effects, inadequate genetic counseling, genetic testing and screening errors, medical mismanagement, negative shifts in attitudes toward medical providers, and unnecessary use of health care resources. Commonly mentioned strategies for preventing/mitigating negative outcomes included: educational outreach and awareness programs for medical providers and the general public, standardized testing and screening processes, and implementing mechanisms for reporting and addressing adverse events. Additional findings, practice and policy implications, and research recommendations are discussed.