Molybdenum oxide (5 to 20 wt.%) supported on calcium or strontium hydroxyapatite were investigated as catalysts for selective oxidation of methanol to formaldehyde. These catalysts were both active and selective, with a maximum yield achieved at 95 % conversion and 96 % selectivity. The main byproducts were CO (3.2 %) and dimethyl ether (DME, 0.7 %). The catalytic performance of the catalysts was measured for up to 600 h at 350 °C. Compared to an industrial iron molybdate catalyst, the hydroxyapatite based catalysts deactivated slower. The active species were found to be a surface layer of MoO_x on the hydroxyapatite support, while excess molybdenum formed crystalline (Ca/Sr)MoO₄, acting as a reservoir replenishing surface MoO_x lost by volatilization with methanol. The excess molybdenum in the form of (Ca/Sr)MoO₄ was found to volatilize significantly slower than the excess MoO₃ in iron molybdate catalysts. The combination of high activity and selectivity with low rate of Mo volatilization makes this class of catalysts interesting for industrial production of formaldehyde.