A search for associated production of a Z boson with an open charm meson is presented using a data sample, corresponding to an integrated luminosity of 1.0 fb-1 of proton-proton collisions at a centre-of-mass energy of 7TeV, collected by the LHCb experiment. Seven candidate events for associated production of a Z boson with a D0 meson and four candidate events for a Z boson with a D+ meson are observed with a combined significance of 5.1 standard deviations. The production cross-sections in the forward region are measured to be αZμ+μ-, D0= 2.50 ±1.12 ±0.22 pb αZμ+μ-, D + = 0.44 ±0.23 ±0.03 pb,where the first uncertainty is statistical and the second systematic. [Figure not available: see fulltext.] © 2014 The Author(s).