The WWgamma triple gauge boson coupling parameters are studied using p[overline p]-->[script-l]nugamma+X([script-l]=e,µ) events at sqrt(s)=1.96 TeV. The data were collected with the D0 detector from an integrated luminosity of 162 pb-1 delivered by the Fermilab Tevatron Collider. The cross section times branching fraction for p[overline p]-->W(gamma)+X-->[script-l]nugamma+X with ETgamma>8 GeV and Delta[script R][script-l]gamma> 0.7 is 14.8±1.6(stat)±1.0(syst)±1.0(lum) pb. The one-dimensional 95% confidence level limits on anomalous couplings are -0.88<Deltakappagamma<0.96 and -0.20<lambdagamma<0.20.