A measurement of the forward–backward asymmetry $${A}_{\mathrm{FB}}$$ of oppositely charged lepton pairs ( $$\mu \mu $$ and $$\mathrm{e}\mathrm{e}$$ ) produced via $$\mathrm{Z}/\gamma ^*$$ boson exchange in pp collisions at $$\sqrt{s} = 8$$ $$\,\mathrm{TeV}$$ is presented. The data sample corresponds to an integrated luminosity of 19.7 $$\,\mathrm{fb}^{-1}$$ collected with the CMS detector at the LHC. The measurement of $${A}_{\mathrm{FB}}$$ is performed for dilepton masses between 40 $$\,\text {GeV}$$ and 2 $$\,\mathrm{TeV}$$ and for dilepton rapidity up to 5. The $${A}_{\mathrm{FB}}$$ measurements as a function of dilepton mass and rapidity are compared with the standard model predictions.