Oral ulcers represent a variable, impressive group of oral lesions. Recurrent Apthous Stomatitis (RAS) is one of the most common oral lesion characterized by single or multiple, round to ovoid painful, recurring ulceration of the oral mucosa. Various etiologies and treatment modalities have been suggested with time by various researchers which leads to the perplexity of thoughts between etiologic, precipitating factors and its prognostic outcome. In our case report,  we have treated a patient, who was diagnosed as Recurrent Apthous Major and was admitted in the hospital for monitoring and better management. Patient was under various systemic medications to provide him relief from secondary infections.  But to relief him from excruciating symptoms, photo–biomodulation (LLLT) with Diode Laser (Dc Laser, 940 Nm) was given following the proper protocol. Patient was discharged from hospital on seventh day and was kept under follow up for 4 months to ensure any recurrence thereafter.