The distribution and abundance of meiobenthos, hydrography and sediment characteristics of three different types of traiditonal prawn culture systems around Cochin were studied for a period of two years (1988-1990). Nematodes were the most dominant group (79.6%) of the total meiofaunal count followed by harpacticoids and polychaetes. Others like oligochaetes, bivalves, ostracods, amphipods and tanaids had only stray occurrences and together formed a meagre 0.30% of the total. The upper 0-5 cm layer harboured 79.5% of the meiofaunal population. The perennial ponds had the highest abundance of meiobenthos (69.9%) followed by canals (17.9%) and seasonal fields (12.2%): The meiobenthic biomass ranged from 0.84 mg/ 10 cm2 to 5.7 mg/lO cm2in different stations. Meiofauna did not show a significant positive correlation with the different environmental parameters. However, during the southwest monsoon period, the population showed a sharp decline. Meiobenthos were found to be abundant at stations where the sand content varied from 60-7870 and silt from 15-29%, and were lowest at stations with high clay content. High content organic carbon also did not favour a high abundance of meiofauna. The presence of nematodes (80%) in the gut content of the prawns indicates a trophic chain involving meibenthos.