Molecular sieves having three-dimensional microporous framework structures of BO.sub.2, AlO.sub.2 and PO.sub.2 tetrahedral units are disclosed. These molecular sieves have an empirical chemical composition on an anhydrous basis expressed by the formula:mR: (B.sub.x Al.sub.y P.sub.z)O.sub.2wherein "R" represents at least one organic templating agent present in the intracrystalline pore system; "m" represents the molar amount of "R" present per mole of (B.sub.x Al.sub.y P.sub.z)O.sub.2 ; and "x", "y" and "z" represent the mole fractions of boron, aluminum and phosphorus, respectively, present as tetrahedral oxides. The use of these molecular sieves as adsorbents, catalysts etc. is also disclosed.