Aims & Objectives: To analyze quality of chest compressions (CC) during resuscitation and its impact on the return of spontaneous circulation (ROSC) in a pediatric animal model of cardiac arrest (CA) using a real-time feedback-device. Methods Depth and rate of CC were measured with an accelerometer (ZOLL®) during resuscitation in an experimental model of asphyxial CA in piglets. Compression depth between 3.8 and 5 cm and a rate between 100 and 120 compressions per minute were considered optimal. Results CC quality was recorded in 19 piglets. Twelve of them (63.2%) achieved ROSC. Only 41.3% of CC were optimal regarding rate and depth. Compression depth was optimal in 48.9%, too deep in 43.2% and too shallow in 7.9%. CC rate was optimal in 80.3%, too fast in 4.6% and slow in 15.1%. Compressions were more shallow and faster in piglets who recovered spontaneous circulation than in those who didn´t (table 1). Optimal compressions (rate and depth) (52.7 ± 25% vs 21.7 ± 16.2% p=0.010) and optimal depth (61.9 ± 28.2% vs 26.5 ± 17% p=0.008) were associated with higher ROSC. Animals who suffered airway bleeding or thoracic injuries had received deeper CC after 3 minutes of CPR, p=0.006. There was a correlation between mean arterial pressure and quality of CC (table 2).Conclusions In this pediatric CA model, only 41.3% of chest compressions were optimal. Optimal quality of CPR was associated with higher survival. Excessive CC depth was associated with airway bleeding or thoracic injuries and increased mortality.