Abstract: Obese adult patients have many dermatoses, such as skin tags, candida infection, cellulite, and intertrigo, but only limited data have been published on obese children and the barrier function of their skin. Sixty-five overweight and obese children (n = 40, BMI 85th–95th percentile; n = 25, BMI > 95th percentile) (aged 8–15; mean age 11.6) and 30 normal-weight controls (aged 7–15; mean age 11.1) underwent a clinical evaluation and calculation of transepidermal water loss (TEWL). Higher weight percentile was associated with a higher incidence of some dermatoses. Skin tags were found in 40% of subjects in the 95th percentile and 2.5% of those in the 85th percentile. Striae distensae were observed in 32% of patients in the 95th percentile and 22.5% of those in the 85th percentile. Plantar hyperkeratosis was observed only in 20% of the 95th percentile subjects and was not observed in the other groups. TEWL values at the forearm site were significantly higher (p < 0.05) in obese children than in the control group, but no significant differences in TEWL values according to BMI level were found between the two groups of obese children. Degree of obesity influences the incidence of some associated dermatoses; skin tags, striae distensae, and plantar hyperkeratosis were more frequent in children in the 95th percentile of BMI. Obesity increases the TEWL rate, suggesting that obese children might become more easily overheated as weight increases, with more profuse sweating because of the thick layers of subcutaneous fat.