The present invention provides a simple and sensitive aqueous method for determining cholesterol in remnant-like particles in a biological sample without the separation of components of the sample. The method comprises contacting the sample with (i) cholesterol esterase, (ii) cholesterol oxidase or cholesterol dehydrogenase, and (iii) phospholipase with a surfactant that inhibits cholesterol oxidase or cholesterol dehydrogenase in lipoproteins other than remnant-like particles in the presence of oxygen or an oxidized coenzyme. Formed hydrogen peroxide or reduced coenzyme is measured and correlated to a quantitative determination of cholesterol in remnant-like particles.