We report a case of right lower abdominal wall and groin abscess resulting from acute appendicitis. The patient was an 27-year-old man who had no apparent abdominal signs and was brought to the hospital due to progressive painful swelling of right lower abdomen and the groin for 10 d. Significant inflammatory changes of soft tissue involving the right lower trunk were noted without any apparent signs of peritonitis. Laboratory results revealed leukocytosis. Abdominal ultrasonography described the presence of abscess at right inguinal site also communicating with the intraabdominal region. Right inguinal exploration and laparotomy were performed and about 250 mL of pus was drained from the subcutaneous tissue and preperitoneal space. No collection of pus was found intraabdominally and subserous acute appendicitis was the cause of the abscess. The patient fully recovered at the end of the second post-operation week. This case reminds us that acute appendicitis may have an atypical clinical presentation and should be treated carefully on an emergency basis to avoid serious complications.