Fluorosis of the primary dentition was determined in 146 children living in a hot, dry African village with a fluoride concentration in the drinking water of 0.98-2.7 ppm. The prevalence of fluorosis was compared using DEAN's (8) and THYLSTRUP & FEJERSKOV's (14) indices. The prevalence varied according to tooth type, being highest in maxillary second molars (25%) and lowest in mandibular central incisors (4.6%). The two scoring systems produced almost identical prevalences of fluorosis but the severity scores varied. Generally THYLSTRUP & FEJERSKOV's index scores were one score higher than DEAN's. The THYLSTRUP & FEJERSKOV index is recommended for future studies.