Conformational searches were performed using molecular mechanics in the gas phase for monocyano-, regioisomers of dicyano-, tetracyano-, and hexacyano- and octacyano-meso-octamethylcalixpyrrole (2) to elucidate the factors responsible for conformational preference. The cyano function has a polarity quite similar to that of the previously investigated carboxamido function, but since its linearity results in fewer conformational possibilities, the computational task as well as interpretation of the results was simplified. Of the components of the Amber* force field, electrostatic and van der Waals attractive forces were typically the most important contributors to the global minimum for the series of compounds investigated. Flattened cone global minima conformations were found when 2 was incompletely substituted. With octasubstitution, significant destabilization of the flattened cone conformation was found relative to the doubly flattened 1,2-alternate due in part to a significant increase in bending energy. This suggests that hydrogen bonding plays a major role in stabilization of the flattened cone conformation of the octacarboxamido compound.