Background: Acute appendicitis is common surgical condition and appendectomy is the treatment of choice in majority of cases. Ac. Appendicitis requires immediate diagnosis and definitive management if delayed may lead to perforation or gangrenous appendicitis that leads to develop post–operative complication, No standardized approach is available hence placed trans–abdominal drain post op to minimize complication. Objectives: 1.To assesses the mode of presentation of Ac & complicated appendicitis. 2. To assess the different treatment modality. 3. To assess the post–operative complication. Methodology: prospective study (cohort) carried out at tertiary care Centre, MUHS Nasik Maharashtra, India. Over 2 year period study from 1 January 2018 to 1 January 2020. 271 patients were enrolled. Results: Involved 5–45 years age group, Median age 25 years, maximum patients reported in 16–20 years, M:F ratio 1:1.39. Diagnosis based on symptoms, signs and laboratory, analyzed by Alvarado‘s score. Patients received preoperative, perioperative & post–operative antibiotics. Also USG, CT &X–ray abdomen, Mcburney‘s muscle splitting incision preferred, in complication Rutherford Morison extension, lanz, for females. Intraoperative findings were inflamed Appendix(33.50 9%), suppurated appendices (29.52%), perforated (10. 33%), gangrenous (14.39%)& appendicolith, abscess, lump in few,it correlated with histopathology. In complication, peritoneal wash& trans–abdominal drain with primary wound closure. Post op complications like SSI, SAIO, wound gape, electrolyte imbalance, paralytic ileus, delayed were incisional hernia total (29.52%). Maximum patients discharged in 4–6 days (37.27%). Conclusion: Young age group confirmed the open appendectomy remains the most effective treatment & trans–abdominal drain for complicated appendicitis associated with preoperative, perioperative and postoperative antimicrobial treatment can definitely minimizes the postoperative complications and good outcome