Simultaneous determination of albumin and IgG has been made on 50 sera and 100 CSF of neurological patients by electroimmunodiffusion (EID) and an automated immunonephelometry (AIN). A new type of gel (mixture of carboxymethyl-cellulose and agarose) was used for the determination of IgG by EID. The statistical comparison between the two methods shows the accuracy and the good reproducibility of automated immunonephelometry.