Pain management becomes important in the treatment of oral mucosal diseases since it can impair the quality of life. Photobiomodulation (PBM) as an alternative therapy, has potency in reducing pain through several mechanisms targeting peripheral nerves in the target tissue. Purpose: To discuss the effectiveness of PBM in the management of four cases of oral mucosal diseases. Case: Four patients, two females and two males, with an age ranging from 24 to 63 years came to the Oral Medicine Department complaining of painful lesions in their oral cavity. Three cases showed ulceration of the oral mucosa and had been diagnosed with recurrent aphthous stomatitis, recalcitrant chronic ulcer, and non-specific chronic sialadenitis. One patient who complained of intense pain and swelling on the right side of the face was diagnosed with post-herpetic neuralgia (PHN). Case Management: PBM was administered in all four cases (976 nm diode laser, three cases with spot size 0.01 cm 2 , fluency 10 J/cm 2 , and one case with spot size 0.5 cm 2 ; fluency 3 J/cm 2 ). Visual analog scale (VAS) control was performed before and after the PBM at each visit. The recorded VAS results show a reduction in pain that started at the post-laser time, with VAS before PBM ranging from 5 to 7 and after PBM ranging from 0 to 4. Three patients were given triamcinolone acetonide 0.1%, chlorhexidine gluconate 0.2% mouthwash, petroleum jelly, and multivitamins. One patient was given mefenamic acid and multivitamins. Conclusion: PBM can be a useful adjunctive treatment to relieve the pain of oral mucosal diseases due to its ability to reduce pain intensity.