Diagnosis of nematode damage and management on an as-needed basis requires assessing nematode soil infestation levels in representative soil samples collected from the target field or a section of the field. Inclusion of roots in the collected soil samples is advantageous and might be necessary in the case of sedentary and migratory endoparasites including the root-knot, cyst and lesion nematodes that complete part or their entire lifecycle in host tissue. However, the accuracy of diagnosing the problem nematode(s) involved and especially determining the level of its infestation will depend largely on the thoroughness of the sampling method, time of sampling, handling and storage of the samples as well as on the biology of nematode species involved.