The purpose of this study was to evaluate if football helmets were correctly fitted in high school football players from 34 randomly selected Wisconsin public high schools. Helmets were evaluated for correct fit by certified athletic trainers with the consent of the head coach. Helmet fit was assessed by examining seven specific criteria selected from standardized helmet fitting guidelines. The criteria selected for examination were as follows: (1) 1-in. (2.5-cm) clearance above the eyebrows, (2) 2-in. (2.5-cm) minimum clearance from nose to face mask, (3) chinstrap centered and tight, (4) jaw pads snug to face, (5) hear holes aligned and tight, (6) adequate coverage of the posterior cranium, and (7) minimal anterior/posterior movement with pressure. Each of the criterion was visually and manually inspected by the certified athletic trainers while the helmet was being worn by the football player. Other collected information included helmet brand, who fit the helmet, and year in school for the football player. In 1671 helmets 3403 fitting errors were observed for an overall fitting error rate (mean ± SD) of 2.04 ± 1.40, range 0 to 7. Of the helmets, 15.4% (n = 258) had no fitting errors, 23.5% (n = 392) had one or two fitting errors, 22.2% (n = 371) had 3 errors, and 15.4% (n = 258) had 4 or more errors. Bike helmets had the highest fitting error rate (2.34 ± 1.45) and highest percentage of helmets with 4 or more errors, 22.6% (n = 113), but Riddell® helmets had the lowest rate (1.84 ± 1.34) and the lowest percentage of helmets with 4 or more errors, 11.9% (n = 99). Freshman players had the highest fitting error rate (2.56 ± 1.44), while senior players had the lowest rate (1.80 ± 1.29). The most common error, 43.3% (n = 724) was inadequate or excessive clearance above the eyebrows. The least common error, 2.9% (n = 49), was adequate coverage of the posterior cranium. Although football helmets cannot prevent all head injuries in high school football, a correctly fitted helmet may decrease the likelihood of sustaining such an injury. Further study in this area is warranted.