Background: Acne vulgaris remains the leading dermatological condition. The efficacy of laser treatment has been supported by many clinical studies, but studies investigating its multidimensional action are lacking. Aim: To comprehensively investigate the efficacy of 1450-nm diode laser treatment in patients with inflammatory acne and provide objective and subjective data for doctors in clinical practice. Methods: This retrospective study included patients with inflammatory acne lesions who underwent three courses of 1450-nm diode laser treatment between October 2019 and August 2020. Facial surface analysis was performed via objective computer assessments using the Canfield VISIA imaging system. Post-treatment subjective assessments were retrieved and analyzed using the clinical global impression–improvement index (CGI-I) and patient global impression of improvement scales (PGI-I). Results: The final analysis included 20 patients. The changes in the porphyrin VISIA system scores demonstrated significant improvement, with median scores being 35.83, 48.83, and 54.83, respectively. The changes in the red area VISIA scores also showed improvement, with the median scores being 48, 50.33, and 58.83, respectively. The average CGI-I scale scores were 2.2 ± 1.01, 1.70 ± 0.80, and 1.50 ± 0.76, respectively (p= 0.001), and the average PGI-I scale scores were 3.10 ± 0.85, 3.10 ± 0.97, and 3.05 ± 0.95, respectively (p= 0.727), with no significant changes observed in sebum production. Conclusions: The present study is the first to provide objective and subjective evidence proving that the 1450-nm diode laser can reduce inflammatory acne lesions.