For an assembled conjugate cam mechanism with two separate oscillating roller followers serving as a conjugation measuring fixture, when the cams rotate, the variation of the subtending angle between the two follower arms can indicate the variation of the cam profile errors. The profile errors of the assembled conjugate disk cams can be indirectly calculated by means of the conjugate variation measurement and the inverse conjugate variation analysis. That is, if a pair of master conjugate cams with known profile errors is available, by means of the measured subtending angle variations of the follower arms induced by a pair of assembled conjugate cams that consists of one master cam and the other being the inspected cam, then the actual profile of the inspected cam can be calculated by applying the inverse conjugate variation analysis. In order to verify the presented concept, experiments meant to calculate the profile errors of a pair of machined conjugate cams were conducted to compare with the measuring results obtained by using a coordinate measuring machine. The experimental results showed that the calculated cam profiles were well consistent with those of the measured ones. The presented method can be an effective alternative means for examining profile errors of assembled conjugate disk cams and could be useful for the quality control in mass production of conjugate cams.