OBJECTIVES: Caution is advised when prescribing antipsychotics to people with dementia. This study explored the determinants of appropriate, evidence-based antipsychotic prescribing behaviors for nursing home residents with dementia, with a view to informing future quality improvement efforts and behavior change interventions. DESIGN: Semistructured qualitative interviews based on the Theoretical Domains Framework (TDF). SETTING AND PARTICIPANTS: A purposive sample of 27 participants from 4 nursing homes, involved in the care of nursing home residents with dementia (8 nurses, 5 general practitioners, 5 healthcare assistants, 3 family members, 2 pharmacists, 2 consultant geriatricians, and 2 consultant psychiatrists of old age) in a Southern region of Ireland. MEASURES: Using framework analysis, the predominant TDF domains and determinants influencing these behaviors were identified, and explanatory themes developed. RESULTS: Nine predominant TDF domains were identified as influencing appropriate antipsychotic prescribing behaviors. Participants' effort to achieve "a fine balance" between the risks and benefits of antipsychotics was identified as the cross-cutting theme that underpinned many of the behavioral determinants. On one hand, neither healthcare workers nor family members wanted to see residents over-sedated and without a quality of life. Conversely, the reality of needing to protect staff, family members, and residents from potentially dangerous behavioral symptoms, in a resource-poor environment, was emphasized. The implementation of best-practice guidelines was illustrated through 3 explanatory themes ("human suffering"; "the interface between resident and nursing home"; and "power and knowledge: complex stakeholder dynamics"), which conceptualize how different nursing homes strike this "fine balance." CONCLUSIONS: Implementing evidence-based antipsychotic prescribing practices for nursing home residents with dementia remains a significant challenge. Greater policy and institutional support is required to help stakeholders strike that "fine balance" and ultimately make better prescribing decisions. This study has generated a deeper understanding of this complex issue and will inform the development of an evidence-based intervention.