The densities of Amoco P-55, P-75, P-100, and P-120 pitch based graphite fibers and their intercalation compounds with bromine, iodine monochloride, nickel (II) chloride, and copper (II) chloride have been measured using a density gradient column. The distribution of densities within a fiber type is found to be a sensitive indicator of the quality of the intercalation reaction. In all cases the density was found to increase, indicating that the mass added to the graphite is dominant over fiber expansion. Density increases are small (less than 10%) giving credence to a model of the intercalated graphite fibers with regions that are intercalated and regions that are not. © 1990.