We describe a general search for resonances decaying to a neutral eμ final state in pp collisions at a center-of-mass energy of 1.96 TeV. Using a data sample representing 344  pb−1 of integrated luminosity recorded by the Collider Detector at Fermilab II experiment, we compare standard model predictions with the number of observed events for invariant masses between 50 and 800  GeV/c2. Finding no significant excess (5 events observed vs 7.7±0.8 expected for Meμ>100  GeV/c2), we set limits on sneutrino and Z′ masses as functions of lepton family number violating couplings.