Objective: Many subjects with dementia present primarily to neuropsychiatric practices because of behavioural and psychological symptoms (BPSD). This study reviewed the profile of clinically-diagnosed dementias and BPSD seen in a pioneer neuropsychiatric practice in Abeokuta, southwestern Nigeria over a ten year period (January1998 -December 2007). Methods: A review of hospital records of all patients with diagnoses of dementia or dementing illness using the ICD-10 criteria as well as specific diagnostic criteria for different dementia phenotypes. Associated BPSD, co-morbidities and treatments were also reviewed. Results: Out of a total of 240,294 patients seen over the study period, 108 subjects met clinical diagnostic criteria for probable dementia giving a hospital frequency of 45 per 100,000. Alzheimer's disease (AD) and Vascular dementia (VaD) were the predominant phenotypes seen in 62 (57.4%) and 18 (16.7%) subjects respectively. Others include mixed dementia (4 cases), frontotemporal dementia (4 cases), Lewy body dementia (3 cases), alcohol-related dementia (3 cases), PD dementia (1 case) and unclassifiable (13 cases). Apathy, night time behaviour, aberrant motor behaviour, agitation and irritability were the most common BPSD features, while hypertension was the most common co-morbidity. Neuroleptics, anticholinergics and anti-hypertensives were most commonly prescribed. Anticholinesterase inhibitors were sparingly used. Conclusion: Probable AD was the most prevalent dementia phenotype seen in this practice. Increased awareness of dementia and better utilization of specific treatments are needed among psychiatrists and primary care practitioners in Nigeria.