This paper endeavors to show that by considering the pressure forces, the viscous drag forces, and the centrifugal forces acting on the journal in a plain journal bearing in oil whip, it is possible to obtain a rational explanation of this phenomenon. The conditions of force equilibrium of the journal lead to two equations, the first of which determines the ratio of frequency of whirl to frequency of rotation in terms of the eccentricity ratio. The second equation relates the eccentricity ratio to the frequency of rotation. These equations therefore suffice to describe oil whip in frequency and amplitude. Numerical studies of the problem indicate some agreement with published experimental studies.