A ship-mounted 153kHz narrow-band ADCP and 1m 2 MOCNESS were deployed between 16 and 24 Sept. 1997 in the Ligurian central zone (~43 o 20'N 7 o 48'E). Results from both instruments showed that the zooplankton community performed vertical migrations that conformed to the classical pattern of ascent at dusk (~18:30h) and descent at dawn (~06:30h). Depth-discrete net samples between 0 and 500m showed that the community was dominated by two species, the euphausiid Meganyctiphanes norvegica (Northern krill) and the pteropod Cavolinia inflexa, which migrated in separate discrete bands that were detectable by the ADCP. Information from the ADCP was used to estimate vertical migration speed in two ways: (i) from the trajectory of the back-scattering bands over time and (ii) from the Doppler-shift vertical velocity measured within depth zones at the corresponding time and depth of these bands. Estimates of the migration speed of C. inflexa were between 2 and 7cms - 1 upwards and between 4 and 7cms - 1 downwards. M. norvegica was estimated to migrate at speeds between 7 and 8cms - 1 upwards and over 11cms - 1 downwards. The consistently lower migration speeds estimated from Doppler measurements as compared with estimates obtained from measuring trajectories of back-scattering bands over time was believed to result from a methodological artefact. The Doppler measurements were nevertheless useful in a relative sense in revealing the relative speed of individuals within swarms. It was shown that individuals at the front of the upwardly migrating band of M. norvegica moved more slowly than those at the rear. These results illustrate the extra biological information that can be obtained by ADCPs compared with conventional echo-sounders.