Objective: Reducing adverse effects in laparoscopic cholecystectomy (LCE) is important to avoid complications. After removal, the porta hepatis and gallbladder bed of liver were treated with pulse width modulated (PWM) red LED light with parameters λ = 625 ± 5 nm, full width at half maximum 17 nm, 76 Hz, duty cycle 23%, 15–30 mW/cm2, and 0.9–1.8 J/cm2. The changes of eight blood parameters were studied: red blood cell, hemoglobin, white blood cell, erythrocyte sedimentation rate (ESR), bilirubin, aspartate transaminase (AST), alanine transaminase (ALT), and amylase. Background data: Other current methods of reducing undesirable effects of LCE significantly affect surgery and are not commonly used in practice. Materialsandmethods: Before LCE, 263 patients were randomized into the control and test groups. Patients in the test group were treated with light radiated for 2 min during the surgery on the bed of the removed gallbladder and porta hepatis. Blood samples were taken before surgery and on the third day after surgery, studied, and compared by nonparametric statistical methods. Results: The test group revealed significant reduction in postsurgery gain of levels of ALT, AST, and ESR compared with the control group. Conclusions: Treatment of the removed gallbladder bed and porta hepatis by red LED PWM radiation during LCE significantly reduces the adverse effects of surgery while increasing its time insignificantly and does not affect the surgical best practices deployed.