Abstract: A crib sheet for retaining an infant in a central region of a crib or bed and preventing such an infant from displacing a blanket covering when unattended. The sheet includes a central pleat which extends along the entire sheet length and is sewed or otherwise fixed in a folded configuration at the ends thereof. A sleeper jacket is attached at an opening across the central pleat to form an integral sleeper unit. The extendable pleat between the fixed ends permits safe movement for the infant without binding the sheet or causing other discomfort.