Introduction: Nodulocystic acne is a severe form of acne which can result in significant damage to the skin with great impact on quality of life. Oral isotretinoin considered to be the best treatment for such cases. Although it has a high rate of success and its efficacy is well established in the treatment of nodulocystic acne, it may occasionally fail to control the disease. Objective: To assess the clinical and biochemical evaluation of the efficacy of isotretinoin in nodulocystic acne. Materials and Methods: The 45 cases for the study were selected from the patients attending Dept. of Dermatology and OPD, Medical College for Women & Hospital (MCW&H), Uttara, Dhaka, Bangladesh during the period January 2019 December 2019. All patients were evaluated for baseline CBP, blood sugar, LFT (AST, ALT, alkaline phosphatase, serum bilirubin), RFT (blood urea, sr. creatinine), sr. lipid profile (sr. triglycerides, total cholesterol, LDL, HDL).Ultrasound abdomen and pelvis was done in women to rule out PCOD. Started on 0.5mg/kg per day of isotretinoin in single daily dose after meals. Evaluated every month for a period of 15-20 weeks. Follow up every month for 3 to 4 months. At the end of every month CBP, LFT, RFT, lipid profile were done. Results: Clinical improvement - 43 out of 45 patients 22.22%(10 patients out of the total 45)- flare up of acne, Dryness and fissuring of lips - 88%, xeroderma - 2%, 2%- epistaxis, myalgias- 4%, desquamation of the palms but not soles was observed- 2% patients, 2% - headache. All routine investigations, LFT, lipid profile were repeated after 1 month and after completion of treatment. Transient elevation in serum triglycerides and total cholesterol was seen in some but not significant enough to require stoppage of treatment or anti hyperlipidemic treatment. Follow up was done for a period of 3 months after completion of treatment. Conclusion: Oral isotretinoin appears to have favorable results and the minimal adverse effects in treatment of carefully-selected patients with nodulocystic acne.