The conformational flexibility and the intramolecular hydrogen bonding of a series of [n.3.3]propellanediols (and related model compounds) was explored. Evidence was obtained from an analysis of NMR coupling constants for solvent-dependent conformational changes related to intramolecular hydrogen bond formation. Gas-phase IR spectroscopy allowed direct observation of both hydrogen bonded and non-hydrogen bonded OH stretching. Molecular mechanics calculations helped identify the key structural features of these molecules. The calculated structures confirmed the possibility of the formation of excellent intramolecular hydrogen bonds (nearly linear, with oxygen-oxygen distances of about 2.8 Å) and allowed an assessment of the basis for the balance of conformations available to the bicyclo[3.3.0]octyl portion of the molecule as a function of the structure of the third propellane ring.