We search for CP violation in the charged charm meson decay D+ -> pi(+)pi(0), based on a data sample corresponding to an integrated luminosity of 921 fb(-1) collected by the Belle experiment at the KEKB e(+)e(-) asymmetric-energy collider. The measured CP-violating asymmetry is [+2.31 +/- 1.24(stat) +/- 0.23(syst)] %, which is consistent with the standard model prediction and has a significantly improved precision compared to previous results.