The geometry of 18 carbon polyprismanes with the number of layers from 3 to 8 and the number of carbon atoms in each layer from 3 to 9 was optimized by semiempirical methods using the MOPAC software package, and their heats of formation were calculated. The data on the heats of formation of bilayer carbon prismanes with the number of carbon atoms in each layer equal to 5-12 were supplemented by the semiempirical PM3 (parametric method) and MINDO/3 (modified intermediate neglect of differential overlap) methods. A comparative analysis with the literature data on the heats of formation of carbon prismanes calculated by empirical (molecular mechanics methods), semiempirical and ab initio methods is carried out.