The impulsively-started flow field for two and three circular cylinders of equal diameter arranged side-by-side has been investigated using particle image velocimetry (PIV), over a transverse pitch ratio range of T/D = 1.0 to 3.0, and for Reynolds numbers from Re = 1500 to 3000. The PIV technique was used to obtain a time history of the instantaneous in-plane vorticity field from the moment of impulsive start, from which the development of the flow was studied. Measurements of vortex strength and vortex position relative to the cylinders were obtained from these data. Two and three cylinder configurations of T/D = 1.0 were found to exhibit a cursory degree of similarity to a single, isolated impulsively-started circular cylinder. Side-by-side configurations of T/D > 1.0 were dominated by the strong gap flow(s) between the cylinders, the vortices generated alongside the gap flow(s), and the formation of a single counter-rotating vortex pair in the far-wake.