Abstract Introduction Early diagnosis and prompt and effective treatment is one of the pillars of malaria control Malaria case management guidelines recommend diagnostic testing before treatment using malaria Rapid Diagnostic Test (mRDT) or microscopy and this was adopted in Nigeria in 2010. However, despite the deployment of mRDT, the use of mRDTs by health workers varies by settings. This study set out to assess factors influencing utilisation of mRDT among healthcare workers in Zamfara State, Nigeria. Methods A cross-sectional study was carried out among 306 healthcare workers selected using multistage sampling from six Local Government Areas between January and February 2017. Mixed method was used for data collection. A pre-tested self-administered questionnaire was used to collect information on knowledge, use of mRDT and factors influencing utilization. An observational checklist was used to assess the availability of mRDT in the six months prior to this study. Data were analyzed using descriptive statistics such as means and proportions. Association between mRDT use and independent variables was tested using Chi square while multiple regression was used to determine predictors of use at 5% level of significance. Results Mean age of respondents was 36.0 ± 9.4years. Overall, 198 (64.7%) of health workers had good knowledge of mRDT; malaria RDT was available in 33 (61.1%) facilities. Routine use of mRDT was reported by 253 (82.7%) healthcare workers. This comprised 89 (35.2%) laboratory scientists/technicians, 89 (35.2%) community health extension workers/community health officers; 59 (23.3%) nurses and 16 (6.3%) doctors. Predictors of mRDT utilisation were good knowledge of mRDT (adjusted OR (aOR):3.3, CI: 1.6-6.7), trust in mRDT results (aOR: 4.0, CI: 1.9 - 8.2), having being trained on mRDT (aOR: 2.7, CI: 1.2 - 6.6), and provision of free mRDT (aOR: 2.3, CI: 1.0 - 5.0). Conclusion This study demonstrated that healthcare worker utilisation of mRDT was associated with health worker and health system-related factors that are potentially modifiable. There is need to sustain training of healthcare workers on benefits of using mRDT and provision of free mRDT in health facilities.