The purpose of this study was to evaluate determinants for utilization of alcohol use screening tools by nurses at Mathari Hospital. The study employed analytical cross sectional study design. Participants were practising nurses deployed at Mathari Hospital. 159 respondents formed the sample size. The study utilised simple random sampling. The average age for most nurses was 42 (±10.6) years, had 18 (±10.6) years’ experience in nursing profession, had 10 (±8.1) years’ experience in mental health and psychiatry nursing. Majority (98.1%, 156) of the nurses had cared for a patient with potentially harmful alcohol use and initiated screening for alcohol use on the patient (56.6%, 90). The findings revealed that majority of the nurses were female (76.1%), Christians (97.5%), diploma holders (47.8%), aged was 42 years, 18 years’ experience in nursing profession, and 10 years’ experience in mental health and psychiatry nursing. In addition, education level of nurses was positively and significantly (r=0.164, p=0.039) related with utilization of SBIRT screening tool. The respondents highlighted the following as key enabling factors: Management support (52.8%), motivation (51.6%), Champion (44.7%) and training (44.7%). Management support was positively and significantly (r=0.322, p=0.000) related with utilization of SBIRT screening tool. Identified barriers to utilization of the SBIRT screening tool were nurses’ own alcohol use (44%), competency gaps (32.7%) and lack of knowledge (49.7%). Nurse’s characteristics had a positive and significant influence on the utilization of alcohol use screening tool (β = 0.612, p= 0.000) at 95% confidence interval. Enabling factors had a positive and significant influence on utilization of alcohol use screening tool (β = 0.226, P= 0.061) at 90% confidence interval. Barriers had a negative and significant influence on utilization of alcohol use screening tool (β = -0.261, P= 0.065) at 95% confidence interval. The adjusted R squared (0.243) revealed that jointly, nurses’ characteristics, enabling factors and barriers explain 24.3% of variations in the utilization of alcohol use screening tool. Enabling factors were observed to have a positive and significant relationship with utilization of alcohol use screening tool (r=0.359, P=0.000) at 99% confidence interval. Barriers have a negative and significant relationship with utilization of alcohol use screening tool (r= -0.132, P=0.097) at 95% confidence interval. The three determinants (nurses’ characteristics, enabling factors, and barriers) only explained eighteen percent of changes in utilization of SBIRT suggesting the existence of other factors that may account for changes in utilization of the screening tool. Keywords: Screening tool, alcohol use, SBIRT, barriers, enabling factors, nurse’s characteristics