In this study, Pratylenchus penetrans which is known the root-lesion nematode were inoculated onto red radish seedlings growing in agar on microscope glass slides. The feeding and penetration behaviour of nematodes were observed for three weeks. Patterns of behaviour identical to those described for other nematodes were recognized. Most nematodes migrated to the root hair zone and selected an epidermal cell by rubbing the cell surfaces with lips and stylet. When feeding stylet thrusting, salivation, predigestion and ingestion phases were recognized. Penetration through cells, fed upon or not, occurred after the nematodes bore a series of holes in the cell wall and forced their way through. Penetration of roots via the root hairs is reported.