ObjectivesTo relate the oral health of individuals with fragile X syndrome (FXS) with their oral characteristics, habits, and difficulties in terms of oral hygiene and the perception of oral health of the guardians.Methods and resultsThis observational transversal study included 31 volunteers who belong to the Portuguese Fragile X Syndrome Association. A questionnaire was presented to guardians, and a head and neck and oral examination was performed to the individuals: decay, missing and filled teeth index (DMFT) = 4.65, gingival index (GI) = 1.01, and simplified oral hygiene index (OHI‐S) = 2.26 and Malocclusion Class Angle II (61.3%) with dental aesthetic index 34.90. A high‐arch narrow palate (71%), accentuated gagging reflex (45.2%), and bruxism (22.6%) were the most common oral characteristics. There was a negative correlation between the several behaviors, attitudes, and habits reported by the guardians and all the indexes of oral health, with significance to the DMFT (P = .032), missing teeth (P = .032), and GI (P = .04).ConclusionThere was a variability in oral characteristics, and these can represent a difficulty in performing oral hygiene. The collected data provide information for the health professionals and guardians to guide the monitoring of patients with FXS as well as to create strategies to improve oral hygiene.