Introduction: Gingival enlargement is usually treated with gingivectomy as an alternative to surgery; however, non-surgical mechanical treatment is another option especially in cases of gingivitis associated with puberty as a result of hormonal changes. Objective: To describe the non-surgical treatment of a 12-year-old patient with gingival enlargement associated with puberty and gingival lesions induced by dental biofilm. Case presentation: The patient presented a localized mild gingival enlargement that relapsed to the first phase of treatment after one month. Three months after physiotherapy sessions with removal of calcified biofilm, a reduction in the percentage of oral hygiene index to “good” was obtained; therefore, surgical treatment was not required. Four years later, there was a complete reduction in gingival enlargement and periodontal pockets. Conclusions: Mechanical periodontal therapy is an effective alternative to reduce gingival inflammation induced by hormones during puberty not requiring surgical intervention to treat gingival enlargement. Other alternatives such as gingivectomies are performed; however, they require more complex, expensive procedures and they can also increase patient morbidity. In that sense, the uniqueness of the non-surgical mechanical treatment is chosen as a feasible option.