An enzyme-linked immunosorbent assay using a vaccine strain of Newcastle disease as antigen has been developed. It allows the control of the drop in the maternal antibody level of 1 and 28 days old chicks. Thus it can be used as alternative to the inhibition of hemagglutination method. A comparative study has shown a good correlation between the enzyme-linked-immunosorbent-assay and the inhibition of hemagglutination.