Zeolite MCM-22 was studied by Al-27 and Si-29 NMR with magic angle spinning (MAS). Bloch-decay and cross-polarization spectra were compared and assigned for as-synthesized and calcined samples with various Al content. The interpretation was assisted by Al-27 quadrupole nutation NMR, It was found that the average Si-O-Si angles corresponding to inequivalent framework tetrahedral sites vary from 138 degrees to 163 degrees. The as-synthesized and calcined materials both contain two kinds of framework tetrahedral Al, but the calcined zeolite also contains two kinds of extraframework octahedral Al. Such results can be interpreted on the basis of the MCM-22 structure proposed by Leonowicz et al. (Science 1994, 264, 1910). However, the detailed assignment of the Si(OAl) peaks is still open to discussion.