In cases of acute unilateral deafness, no consensus exists as to whether tympanotomy and sealing of the round window should be performed routinely. To further address this issue, we conducted a retrospective study of pre-, intra-, and postoperative findings in 97 patients who had undergone exploratory tympanotomy (EXT) after the onset of sudden and severe unilateral deafness. Our goal was to ascertain, if we could, whether the benefits of EXT outweigh the risks. We also took into account the effects of perilymph fistula (PLF) on the etiology of sudden hearing loss and postoperative outcomes. We found that routine EXT was indeed beneficial for these patients. It was associated with a very low surgical complication rate, and its effects on hearing as assessed by objective measures were beneficial. The greatest benefits were seen in patients who underwent EXT within 7 days after the onset of their hearing loss. With respect to PLF, we found that the presence or absence of the “typical history” of PLF (i.e., a sudden unilateral hearing loss within 48 hours after a precipitating trauma or physical exertion) had no bearing on whether a PLF was actually present in our group; nor was vertigo a reliable predictor of PLF. We recommend that EXT be performed on all patients with new-onset acute unilateral deafness, barring any contraindications, of course. The absence of a typical history of PLF should not dissuade the surgeon from proceeding with EXT.