Three new pyridocarbazoles, namely, 11-pyrido(4,3-a)-, 11-pyrido(3.4-a)-, and 10-pyrido(3,4-b)- or 9-Pyrido(4,3-c)-carbazole have been synthesized from the hydrazones of cyclohexanone and 5-, 8-, and 7-hydrazinoisoquinoline respectively by ring closure and dehydrogenation of the resulting tetrahydropyridocarbazoles. In unsuccessful attempts to determine which of the two possible pyridocarbazoles is formed from the hydrazone of cyclohexanone and 7-hydrazinoisoquinoline, 11-metftyl-10-pyrido(3,4-b)carbazole was also synthesized. The hydrazone of cyclohexanone and 7-amino-8-chloroisoquinoline failed to undergo ring closure.