We present the results of a search for second generation leptoquarks S2 using 19.3pb−1 of data collected at the Collider Detector at Fermilab (CDF) in pp¯ collisions at s=1.8 TeV during the 1992–93 collider run. We have searched for S2S2¯ pairs assuming that each leptoquark decays to a muon + quark with a branching ratio β. We find two candidate events, consistent with an expected background of 1.11±0.48. We obtain upper limits on σ(pp¯→S2S2¯)β2 as a function of MS2. Using a Monte Carlo prediction for S2S2¯ pair production, we exclude MS2<131GeV/c2 for β=1 and MS2<96GeV/c2 for β=0.5 at 95% C.L.