Abstract: Improved acidic zeolite rho and ZK-5 catalysts for conversion of methanol and ammonia to dimethylamine are disclosed. The acidic zeolite rho catalyst is prepared by calcining zeolite NH.sub.4 -rho or H-rho in the presence of steam. The acidic zeolite ZK-5 catalyst is prepared by calcining zeolite NH.sub.4 -ZK-5 or H-ZK-5 in the presence of steam. An acidic zeolite rho which has been prepared by calcining zeolite NH.sub.4 -rho in a vertical furnace in the presence of ammonia is disclosed. Processes for producing dimethylamine with the specified catalysts are also disclosed.