A device for supporting and positioning an infant, particularly a premature infant, in a tucked prone position. An elongated base layer extends lengthwise from a head end to a feet end, and includes, in order, a head support portion having a width at least sufficient to fully support the head of the infant, a torso support portion having a width sized to correspond to the width of the torso of the infant, and a pelvis support portion terminating in an upwardly extending rear support for the buttocks of the infant. Arm recesses are formed in the torso support portion, and pair of upwardly and rearwardly extending lateral supports extend lengthwise from the arm recesses to the feet end of the device. Leg recesses are defined between, on the one hand, the upwardly extending lateral supports, and, on the other hand, the pelvis support portion and the upwardly extending rear support.