A laser-modified centrifugal analyzer was used to develop kinetic light scattering methods for the measurement of human immunoglobulins IgG, IgA, and IgM. Comparison of equilibrium light scattering methods with kinetic procedures for IgG and IgA demonstrate equivalent precision and relative accuracy. However, quantitative results obtained by equilibrium and kinetics methods for IgM were found to differ significantly. Recovery studies performed with purified IgM have shown that both methods can yield quantitative results in the normal range. Our observations demonstrate that the technique offers a viable and in some respects a superior alternative to other methods currently used in the clinical laboratory.