Garengeot´s hernia corresponds to the presence of the appendix within a femoral hernia, associated or not with acute appendicitis. The diagnosis of this uncommon situation is usually done during surgery. Furthermore, the clinical presentation as necrotizing fasciitis is a rare condition. We report a 54 years old obese hypertensive woman with rheumatoid arthritis of 40 years of evolution treated with methotrexate and prednisone. She consulted for pain and erythema in the right inguinal region. Laboratory revealed leukocytosis and an elevated C-reactive Protein. Suspecting a cellulitis, the patient was admitted for antimicrobial therapy. A pelvic magnetic resonance imaging showed a perforated acute appendicitis in an inguinal hernia with extensive pelvic cellulitis associated with signs of fasciitis. At surgery, an extensive groin and pubic fasciitis was evident, with a necrotic and perforated appendix within a femoral hernia. Surgical debridement, open appendectomy, and femoral hernioplasty without mesh were carried out. Vacuum-assisted closure was installed in the coverage defect. Three surgical debridement procedures were required for the closure of the wound. Two weeks after the first surgical procedure, the patient was discharged in good condition. During the follow-up, she evolved with a surgical wound dehiscence, which was managed with wound dressings until closure.Garengeot´s hernia corresponds to the presence of the appendix within a femoral hernia, associated or not with acute appendicitis. The diagnosis of this uncommon situation is usually done during surgery. Furthermore, the clinical presentation as necrotizing fasciitis is a rare condition. We report a 54 years old obese hypertensive woman with rheumatoid arthritis of 40 years of evolution treated with methotrexate and prednisone. She consulted for pain and erythema in the right inguinal region. Laboratory revealed leukocytosis and an elevated C-reactive Protein. Suspecting a cellulitis, the patient was admitted for antimicrobial therapy. A pelvic magnetic resonance imaging showed a perforated acute appendicitis in an inguinal hernia with extensive pelvic cellulitis associated with signs of fasciitis. At surgery, an extensive groin and pubic fasciitis was evident, with a necrotic and perforated appendix within a femoral hernia. Surgical debridement, open appendectomy, and femoral hernioplasty without mesh were carried out. Vacuum-assisted closure was installed in the coverage defect. Three surgical debridement procedures were required for the closure of the wound. Two weeks after the first surgical procedure, the patient was discharged in good condition. During the follow-up, she evolved with a surgical wound dehiscence, which was managed with wound dressings until closure.