Particle image velocimetry (PIV) is used to study a circular zero-net-mass-flux (ZNMF) jet in cross-flow. ZNMF jets are formed using the working fluid of the system without net transfer of fluid mass into the system during one period of oscillation. Two ZNMF jets in cross-flow are investigated in this study. They are characterised by Rej = 1240, R = 4.6, St = 0.016, and Rej = 2960, R = 7, St = 0.014. Phase-averaged vector fields in the jet near-field are presented and the time dependent volume-flow is calculated to study the formation of the jets. Ensemble-averaged vector fields in the jet far-field are presented to study the mean jet structure. The vector fields are used to determine jet trajectory and the velocity variation along the trajectory. These results are discussed and compared to continuous and pulsed jets in cross-flow. Jet formation is found to be similar to free ZNMF jets. Jet development is found to be similar to free pulsed jets. Penetration and far-field velocity decay are found to be similar to continuous jets in cross-flow.