Objective: The aim of the research is to apply the Nd:YAG, Semiconductor, He-Ne laser to kill Micrococcus spp. bacteria isolated from various human cancers. Study Design: The clinical study design for this research was case–control in analytical and Cross-sectional in descriptive. Backgrounds: Carcinobacteria are bacterial infections organisms that cause cancer by cause mutate of one or several genes. Micrococcus spp.is a genus of non-spore forming Actinomycetes, gram positive, opportunistic pathogen for the immunocompromised patients, related to bacteremia, ventricular shunt, continuous ambulatory peritoneal dialysis peritonitis and central catheters. septic arthritis, meningitis, intracranial abscesses and endocarditis. Methodology: Study patients, specimens, collection of bacteria from cancer patients during malignant tumor eradication. Applying and exposing to Nd:YAG laser at different times. Results: The number of live cells and the percentage of killing of Micrococcus spp. bacteria after exposing them to radiation emitted from Nd:YAG, Semiconductor, He-Ne laser at different times including (5, 10, 20, 30) and comparing them with the control, with (2-4) replications. Conclusion: The conclude that He-Ne, Semiconductor and Nd:YAG lasers are very effective and powerful in killing Micrococcus spp. bacteria isolated from leukemia, liver and colon cancer at different times and the longer the exposure time the higher the killing rate.