BACKGROUND Some national resuscitation guidelines advocate using sustained initial inflations (2-3 s) for babies requiring resuscitation. Inflation times ≥10 s have been used for preterm infants. OBJECTIVE This study examines the ability of operators of varying experience to provide a sustained inflation using three different manual ventilation devices. METHODS We compared a self-inflating bag, a flow-inflating bag and a pressure-limited T-piece device. Fifty clinical staff members from five professional groups gave a sustained inflation with a target peak pressure of 30 cm H2O and target duration of 10 s to an internal leak-free manikin. We measured peak inflating pressure (PIP) and mean inflating pressure (MIP) during the sustained inflation, and the duration of inflating pressure (IP) >20 and 25 cm H2O. RESULTS Median (IQR) duration of IP >25 cm H2O was: self-inflating bag 2.5 s (0.8-5.7), flow-inflating bag 10.6 s (8.4-12.9) and the T-piece 10.7 s (8.9-11.9). There was a weak correlation between experience using a self-inflating bag and longer inflation times (R = 0.290, p = 0.041). When compared with the T-piece, the flow-inflating bag had lower mean MIP (27.0 ± 1.8 vs. 28.8 ± 2.0 cm H2O) and higher mean PIP (32.3 ± 3.7 vs. 29.8 ± 1.8 cm H2O). There were no differences in performance between operator groups. CONCLUSIONS The T-piece provided consistent PIP during a single 10 s sustained inflation with less variation in pressure compared with the flow-inflating bag. Sustained inflations >3 s were difficult to achieve with a self-inflating bag.