Objective: This study evaluated clinically and radiographically, the healing in chronic apical lesions using low level laser therapy (LLLT).   Methods: Twenty female patients between the ages of 20 and 30 years with chronic apical lesions in anterior maxillary teeth diagnosed on the basis of their clinical signs and symptoms and radiographic findings were included in the study. The patients were randomly divided into two main groups according to treatment plan: group I; received conventional endodontic treatment only, group II; received conventional endodontic treatment and then LLLT was used. The low level laser was applied for 120 seconds in the session for three sessions in week for four weeks and the selected parameters were (200 mw, 810 nm, CW). The healing was evaluated clinically, radiographically. Clinically to record pain, swelling, or any other adverse event that occur after treatment for one week.  Radiographically to evaluate bone density and area of periapical lesions using cone beam computed tomography (CBCT) and image fusion. Images were obtained immediate after obturation and after the three follow up periods (1, 3 and 12 month) . Results: clinical signs and symptoms decreased in the lased group faster than conventional group. Pain reduction in the laser group was more effective than the conventional group without significant difference. Bone density analysis   showed that Laser had significantly higher bone density after 1 ,3 and 12 month evaluation periods compared to control group (P<0.05). Comparing the area values of control and laser groups, a significant difference was found throughout the three evaluation periods compared to the area immediate after obturation.   Conclusions: Based on the results of this study; LLLT favored the healing process of apical lesions especially when combined with nonsurgical endodontic treatment. Image fusion and CBCT can provide an accurate and reproducible method for assessment the healing of periapical lesions.