The distribution of zooplankton biomass and species abundance in relation to biological and physical factors is important in understanding the structure and functioning of marine plankton communities. Zooplankton samples from the Northern Benguela Upwelling region, off Walvis Bay were collected in September 2010 with a 1 m2 double Multiple Opening and Closing Net and Environmental Sensing System (MOCNESS) and a 150 kHz broadband vessel mounted Acoustic Doppler Current Profiler (VM-ADCP) to examine the temporal distribution and taxonomic composition of mesozooplankton during an upwelling season. The results of the samples collected at discrete depths from the station located at the shelf break during daytime and night-time are presented. Generally, mesozooplankton displayed a bimodal vertical distribution of biomass and abundance, with concentrations in the surface layer (0-80 m) and greater depths (>200 m). This mode of distribution was interpreted to be an apparent attempt to avoid the thermocline and the oxygen minimum zone. The scarcity of zooplankton within the thermocline and the oxygen minimum zone seemed to indicate that the layers act as an effective barrier to zooplankton migrations. The calanoid copepods were the numerically most abundant mesozooplankton. The net catches and ADCP measurements both showed that the zooplankton community performed diel vertical migrations (DVM) that conformed to the classical pattern of ascent at dusk and descent at dawn. Diel vertical migration was one of the factors that were attributed more to the observed distributional patterns of mesozooplankton. Not all mesozooplankton performed vertical migrations, but mesozooplankton in the size range 0.5-2 mm, which composed mainly of calanoid copepods, were responsible for most of the vertical migrations. The net catches and ADCP. measurements were compared. The acoustic backscatter cross-section (ABSC) as a measure for biomass generally did not gave significant correlations to mesozooplankton and krill biomass. Although more variation in net catches and ADCP measurements could be account for, the night-time relationship was inverse. This resulted from the mismatch of measurements depths by the instruments, notably in the surface layer. The results from both the net catches and ADCP measurements proved to be a useful combination in providing more insight into the distribution patterns of mesozooplankton on a temporal scale, despite the limitations of the ADCP.