The rotational correlation time, tau(R), is important to an analysis of the physical processes underlying proton relaxation enhancement by paramagnetic contrast agents. In this study, we report the successful applications of theoretical and experimental electron paramagnetic resonance (EPR) techniques to VO(DTPA) (DTPA diethylenetriaminepentaacetic acid) in order to describe rotational dynamics of the paramagnetic complex, which is a model for similar sized paramagnetic contrast agents. EPR results are compared to nuclear magnetic relaxation dispersion (NMRD) measurements and are found to be in excellent agreement. Moreover, the distances of closest approach of protons to the central metal ion inferred from EPR, NMRD, and electron spin echo envelope modulation measurements all coincide. The data derived from EPR and NMRD for VO(DTPA) have been applied to model characteristics of Gd(DTPA). The results show that "second-sphere" contributions to proton relaxation are not negligible. This work establishes a basis for the applications of EPR to study the rotational dynamics of virtually any type of paramagnetic contrast agent of interest.