Liquid metal two-phase flows in metallic vessels were studied by using high frame-rate neutron radiography. Both a bubble column and a gas-lift loop arrangement have been considered. Liquid velocity field of two-phase flow in a flat bubble column with rectangular cross-section was measured precisely by the particle tracking velocimetry. In a gas-lift loop, simultaneous measurements of void fraction by using high frame-rate neutron radiography and four-sensor probe were also performed to observe the bubble-probe interaction. Asymmetric Abel inversion was applied to compare the radial void fraction profiles. Measured radial void fraction profiles obtained by neutron radiography and electrical conductivity probe agreed well with each other. From these measurements, the measurement error and basic characteristics of gas-liquid metal two-phase flow were clarified. © 2005 Published by Elsevier B.V.