The microstructural origin of magnetic anisotropy in a magnetron in‐line sputter‐deposited CoPtCr/Cr magnetic thin‐film disk was examined by mapping magnetic properties and microstructure. The film coercivity (Hc), remanence‐thickness product (Mr&dgr;), and coercivity squareness (S*) were determined as a function of radial (r) and angular (&thgr;) co‐ordinates using a transfer curve magnetometer. The observed variations inHc,Mr&dgr;, andS* across the disk were 85 Oe, 0.15 emu/cm2, and 0.03, respectively. The angular variation in magnetic properties showed a sinusoidal pattern with the maxima corresponding to the regions where the tracks were parallel (&thgr;=270°) to the pallet movement direction. High‐resolution scanning transmission electron microscopy showed subtle differences in the Co‐alloy grain morphology and crystallographic orientation between &thgr;=270° and &thgr;=360° locations. The grains were equiaxed in general except for a small fraction of grains elongated in the direction of pallet movement. Lattice images clearly showed that about 45% of the Co‐alloy grains had in‐planecaxes and a preferred alignment of thecaxes along the texture groove. A greater preference for thecaxes to lie along the texture line was observed for the &thgr;=270° location. A coherency stress‐based model is proposed to explain the preferredc‐axis alignment. While the crystalline anisotropy appears to be the main factor responsible for the magnetic anisotropy, both crystalline and shape anisotropies contribute to the magnetic anisotropy variations.