To investigate the role of carbonic anhydrase in the recovery of skeletal muscle from anoxia, pH and cell phosphates were measured by ³¹P Nuclear Magnetic Resonance in superfused newborn rabbit myotubes and cultured mouse soleus cells (H-2K^b-ts a58) after approximately 2 to 3.5 hours without superfusion. In control studies, pH and phosphocreatine fell and Pi rose during anoxia, and recovered within less than 10 minutes after re-perfusion began. A carbonic anhydrase inhibitor, acetazolamide, and dimethylamiloride, an inhibitor of the Na⁺/H⁺ antiporter, NHE1, delayed the recoveries of pH, phosphocreatine and Pi for more than 10 minutes, but the rate of recovery, once initiated, was unchanged. In the presence of the inhibitors, after re-perfusion started, the pH did not rise immediately in spite of a large inwardly directed HCO₃^- gradient, suggesting HCO₃^- movement was unimportant in acid elimination. Lactate, measured by its methyl protons, rose during anoxia and did not fall after an hour of re-perfusion, could not have eliminated protons by co-transport. We conclude that NHE1 is the major exporter of protons by skeletal muscle in recovery from a period of anoxia and that it is essential for carbonic anhydrase to be attached to NHE1 in order to activate it. The mechanism of late recovery of pH could be the mobilization of another proton transporter or removal of the inhibition of the Na⁺-H⁺ antiporter. Inhibition of carbonic anhydrase in skeletal muscle retards acid removal and modifies muscle metabolism significantly after anoxia.