Endometriosis, a common estrogen-dependent disease affecting premenopausal women, often begins in early adolescence but is commonly diagnosed later in life. Deep infiltrating endometriosis (DIE) is the most aggressive form, characterized by deep tissue infiltration and reduced quality of life. The prevalence of DIE in adolescents is unknown due to diagnostic challenges and underestimation of symptoms. Dysmenorrhea, chronic pelvic pain, and dyspareunia are common symptoms. Ultrasonography is the primary imaging technique, but magnetic resonance imaging (MRI) is preferred for complex cases. Diagnostic laparoscopy is used when conventional treatments fail. Early medical and surgical interventions can improve quality of life and fertility but may also lead to persistent symptoms due to surgery. This narrative review aims to report the prevalence of DIE in adolescents, discuss pathogenetic theories, and explore management strategies, including diagnostic challenges and treatment options. The pathogenesis of DIE remains controversial, with various hypotheses involving genetic, epigenetic, and immunological factors. The prevalence of DIE in adolescents varies widely, and imaging techniques have limited sensitivity for early-stage disease. Dysmenorrhea is a critical symptom, often overlooked, and should be investigated in adolescents with severe symptoms. Adenomyosis, a related condition, often coexists with DIE and requires careful evaluation. Treatment options include progestins, combined oral contraceptives, and GnRH agonists, with surgery considered only when medical treatments fail. Ovarian tissue cryopreservation is an option for fertility preservation. Timely diagnosis and appropriate management are crucial for improving outcomes in adolescents with DIE.Endometriosis, a common estrogen-dependent disease affecting premenopausal women, often begins in early adolescence but is commonly diagnosed later in life. Deep infiltrating endometriosis (DIE) is the most aggressive form, characterized by deep tissue infiltration and reduced quality of life. The prevalence of DIE in adolescents is unknown due to diagnostic challenges and underestimation of symptoms. Dysmenorrhea, chronic pelvic pain, and dyspareunia are common symptoms. Ultrasonography is the primary imaging technique, but magnetic resonance imaging (MRI) is preferred for complex cases. Diagnostic laparoscopy is used when conventional treatments fail. Early medical and surgical interventions can improve quality of life and fertility but may also lead to persistent symptoms due to surgery. This narrative review aims to report the prevalence of DIE in adolescents, discuss pathogenetic theories, and explore management strategies, including diagnostic challenges and treatment options. The pathogenesis of DIE remains controversial, with various hypotheses involving genetic, epigenetic, and immunological factors. The prevalence of DIE in adolescents varies widely, and imaging techniques have limited sensitivity for early-stage disease. Dysmenorrhea is a critical symptom, often overlooked, and should be investigated in adolescents with severe symptoms. Adenomyosis, a related condition, often coexists with DIE and requires careful evaluation. Treatment options include progestins, combined oral contraceptives, and GnRH agonists, with surgery considered only when medical treatments fail. Ovarian tissue cryopreservation is an option for fertility preservation. Timely diagnosis and appropriate management are crucial for improving outcomes in adolescents with DIE.