Extracorporeal membrane oxygenation (ECMO) is a rescue treatment used in children and adults with reversible cardiorespiratory failure. The role of ECMO is not fully established in pediatric sepsis. In this retrospective single-center study, we aimed to investigate risk factors and survival in pediatric septic shock supported with peripheral cannulation ECMO. All patients aged 30 days to 18 years treated between 2007 and 2016 with ECMO for septic shock were included. Of 158 screened patients, 31 were enrolled in the study. The P/F ratio was 48 ± 22 mm Hg, b-lactate 8.5 ± 6.6 mmol/L, p-procalcitonin 214 (IQR 19–294) μg/L, and 2 (1–2) vasoactive drugs were infused. The number of organ failures were 3 (3–4). Ten patients were commenced on venovenous and 21 on venoarterial ECMO. Survival from ECMO was 71%, and 68% survived to hospital discharge. Hospital survival was 80% for venovenous ECMO and 62% in venoarterial support (p = 0.43). Factors associated with in-hospital mortality were high b-lactate (p = 0.015) and high creatinine (p = 0.019) at admission. Conversion between modalities was not a risk factor. Sixty percent were alive at long-term follow-up (median 6.5 years). Peripheral cannulation ECMO is feasible in pediatric septic shock. Treatment should be performed at high-volume ECMO centers experienced in sepsis, and central or peripheral type and ECMO modality according to center preference and patient’s need.