Background: Supracondylar fractures are the most common elbow fractures in children, with Gartland type II fractures posing treatment controversies regarding conservative casting versus operative fixation. Optimal management remains debated to achieve the best functional and radiological outcomes while minimising complications. Aim of the Study: The aim of this study was to compare conservative casting and operative treatment by K-wire in Gartland type II supracondylar fracture in children. Methods: This observational comparative study was conducted in the Department of Orthopaedics, President Abdul Hamid Medical College Hospital, Kishoreganj, Dhaka, Bangladesh from January 2024 to May 2025. This study includes 50 paediatric patients presenting with Gartland type II supracondylar fractures of the humerus. The participants were divided into two groups each containing 25 patients: Group a included patients treated with conservative casting and Group B include patients treated with K-wire fixation. Result: Excellent outcomes were observed in 64% of Group A and 80% of Group B. The operative group showed significantly better extension recovery (mean extension lag: 2.2° vs. 3.4°, p=0.01). Baumann’s angle, flexion range, and fracture union times were similar between groups. Hospital stay was significantly shorter in the conservative group. Complications differed, with loss of reduction and malunion in Group A, and pin site infections and nerve injuries in Group B. Conclusion: Both conservative casting and operative K-wire fixation are effective for Gartland type II fractures. Operative treatment showed trends towards better extension outcomes and fewer reductions lost, while conservative management effectively avoided surgical risks with reduced hospital stay.