A detailed theoretical treatment based on Gaussian beam theory is provided for optical scanning holography [ J. Opt. Soc. Am. A 2, 512 ( 1985)]. Topics addressed include the derivation of the impulse response for the optical scanning holographic system, methods of achieving off-axis holographic recordings, reconstructed image resolution, magnification, and distortion. Also presented is experimental verification of the technique based on measurements of the hologram of a simple transmissive slit object.