Introduction: Arthroscopic lavage is a well-established, minimally invasive treatment for septic arthritis (SA) in adults, but the use of arthroscopy in the pediatric population is typically restricted to sports injuries and deformity. Previous research on arthroscopic lavage of septic joints in the pediatric population has been limited to case reports and small case series of older children. As such, we aimed to evaluate the safety and efficacy of arthroscopic treatment of SA in various joints in very young children. Methods: Between 2011 and 2015, 24 children (aged 3wk to 6 y) were treated for SA with arthroscopic lavage. A single portal was adequate for both inflow and outflow in most cases. A second portal was used in all knees and in other joints for synovectomy, when indicated. Drains were placed through the portal site and remained in place for 2 to 3 days. Antibiotics were managed by the infectious disease service. Results: Nine hips, 9 knees, 4 ankles, and 2 shoulders were included. Portal placement, visualization, and adequate lavage were straight forward in all joints. There was 1 transient femoral nerve palsy and no other arthroscopy-associated complications (iatrogenic damage, difficult drain placement, or conversion to open). Two patients required repeat arthroscopic lavage for disease eradication, one of which required a second admission. A third patient underwent open irrigation following arthroscopic lavage with a resultant 1.125 average procedures per subject. At final follow-up (2 to 49 mo, average 16 mo), no recurrence of infection or decreased range of motion was noted. Conclusions: Arthroscopic lavage appears to be a safe, quick, and effective alternative to open arthrotomy for the treatment of SA in very young children. It is feasible in any large joint even in the infantile population, allowing for improved visualization and irrigation with little soft-tissue dissection and morbidity. Our relatively simple technique and positive results should encourage regular use of arthroscopic treatment of SA even in very young children. Level of Evidence: Level IV-case series.