A bstract Angular distributions of the decay B + → K ∗ (892) + μ + μ − are studied using events collected with the CMS detector in $$ \sqrt{\mathrm{s}} $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msqrt> <mml:mi>s</mml:mi> </mml:msqrt> </mml:math> = 8 TeV proton-proton collisions at the LHC, corresponding to an integrated luminosity of 20.0 fb − 1 . The forward-backward asymmetry of the muons and the longitudinal polarization of the K ∗ (892) + meson are determined as a function of the square of the dimuon invariant mass. These are the first results from this exclusive decay mode and are in agreement with a standard model prediction.