Background  There is a known relationship between melanocytic nevi (MN) and cutaneous melanoma. MN are related to genetic and environmental factors, and the latter appear to be more important in childhood.

Objectives  To determine the prevalence of MN and its relationship with phenotypic traits and sun exposure habits in 8- to 10-year-old children.

Subjects and methods  We performed a cross-sectional study of 8- to 10-year-old primary school children in the city of Granada (Spain), gathering data on phenotypic traits, sun protection measures, sunburn frequency and the number and density of MN.

Results  We detected a mean of 19.38 MN per child, predominantly <2 mm in diameter. MN count was associated with low phototype, and was higher in boys vs. girls with low phototype. MN were more numerous with higher age. The largest number of MN of all sizes was detected in 10-year-old boys. MN were most frequently located on the torso and other sites intermittently exposed to sunlight.

Conclusions  A higher MN count is associated with lower phototype (blonde hair and fair skin) and higher age. The mean number of MN, including those of smaller size (<2 mm), was elevated in our series, especially on intermittently exposed sites.