Background:: We studied the patient and non-patients factors of inappropriate psychotropic drug (PD) prescription for neuropsychiatric symptoms (NPS) in nursing home patients with severe dementia. Methods:: In a cross-sectional study, the appropriateness of prescriptions was explored using the Appropriate Psychotropic drug use In Dementia (APID) index sum score. This index assesses information from medical records on indication, evaluation, dosage, drug–drug interactions, drug–disease interactions, duplications, and therapy duration. Various measurements were carried out to identify the possible patient and non-patient factors. Linear multilevel regression analysis was used to identify factors that are associated with APID index sum scores. Analyses were performed for groups of PDs separately, i.e. antipsychotics, antidepressants, anxiolytics, and hypnotics. Results:: The sample consisted of 338 patients with a PD prescription that used 147 antipsychotics, 167 antidepressants, 85 anxiolytics, and 76 hypnotics. It was found that older patients and more severe aggression, agitation, apathy, and depression were associated with more appropriate prescriptions. Additionally, less appropriate prescriptions were found to be associated with more severe anxiety, dementia diagnoses other than Alzheimer dementia, more physician time available per patient, more patients per physician, more years of experience of the physician, and higher nurse's workload. Conclusions:: The association of more pronounced NPS with more appropriate PD prescriptions implies that physicians should pay more attention to the appropriateness of PD prescriptions when NPS are less manifest. Non-patient-related factors are also associated with the appropriateness of PD prescriptions. However, especially considering that some of these findings are counter-intuitive, more research on the topic is recommended.