The mesoporous molecular sieves of the type MCM-41 with different pore openings (40, 64 and 80 Å) were used as catalysts in the gas-phase methylation of 2-naphthol by methanol at 473 K. Their catalytic activity was compared with that of BEA, SAPO-5 and SAPO-11. The molar ratio of 2-naphthol : methanol was varied from 1 : 4 to 1 : 6. The alkylation of the hydroxyl group (O-alkylation) as well as of the aromatic ring (C-alkylation) proceeded. The best yield of 2-methoxynaphthalene was achieved using MCM-41 40 Å and molar ratio 2-naphthol : methanol = 1 : 6.