The55Mn NMR has been observed in the paramagnetic state of the antiferromagnet MnO. The separation between the absorption derivative extrema of the55Mn NMR is55(&dgr;H)≃340 Oe, in satisfactory agreement with the predictions of exchange narrowing of hyperfine broadened nuclear magnetic resonances in paramagnetic media. The55Mn NMR frequency shift55a=(&dgr;v/v) is found to be temperature dependent, varying from about −11.75% to −9.3% in the range 130° to 350°K. From the observed linear dependence of55aon the magnetic susceptibility, the hyperfine coupling constant is determined to be55A=−(81.5±1.6)×10−4cm−1. Combining the17O NMR data of O'Reilly and Tsang with the55Mn NMR data yields a value for the17O transferred hyperfine coupling constant of17A=(2.46±0.04)×10−4cm−1.