The inclusive D s ± production asymmetry is measured in pp collisions collected by the LHCb experiment at centre-of-mass energies of s√=7 and 8 TeV. Promptly produced D s ± mesons are used, which decay as D s ± → ϕπ±, with ϕ → K+K−. The measurement is performed in bins of transverse momentum, pT, and rapidity, y, covering the range 2.5 < pT < 25.0 GeV/c and 2.0 < y < 4.5. No kinematic dependence is observed. Evidence of nonzero D s ± production asymmetry is found with a significance of 3.3 standard deviations.