This paper details the non-intrusive optical measurement of droplet velocity in two-phase flashing propane jets. Centreline and lateral profiles of axial velocity are presented and compared with a simple jet model. Non-intrusive techniques are presented as the only viable option for obtaining accurate data in such non-equilibriated environments. Even with these techniques, careful and detailed data analysis is required to ensure that only valid data is obtained and reported, especially in the near-field regions of such jets. (C) Crown