There has been an increasing global interest in understanding, documenting, and monitoring water, sanitation, and hygiene (WASH) services in schools. This study is the first to identify existing WASH-in-school capacities and understand the magnitude of the gaps in WASH coverage in schools in the Northern Cameroon, a region of the country marked by recurrent sanitary emergencies, the highest prevalence of acute malnutrition, and representing the largest and heaviest focus of food and water insecurity. Using a cross-sectional design, relevant authorities of 176 schools in Garoua, were interviewed. The survey guide included core questions for monitoring WASH in schools from recommended guidelines. Eleven indicators-related variables were extracted from data to calculate the WASH-in-school indicators composite score, which could be used as a more reliable and useful tool for comparison across settings and can contribute to harmonize data with WASH in schools related indicators applied in national surveys. The results of this research showed suboptimal drinking water supply systems and sanitation facilities whereas most schools had hand washing points available. However, activities that aimed to promote and sustain a WASH positive environment among children still need to be put in place. The WASH-in-school indicators composite score predictive value corroborated the disparities related to WASH access in schools located in Garoua. This score hence provides an assessment of the spatial dimensions of reduced access to water in schools, improper hygiene practices, and inadequate sanitation facilities. Such a score could be used to identify hotspots lacking WASH infrastructural facilities and strategize optimal interventions to reduce the incidence of WASH related diseases in schools.