The aim of this study was to evaluate the results of inferior oblique muscle recession in certain cases of superior oblique paralysis. Twenty-three patients with moderate hyperaction of the inferior oblique muscle, secondary to paralysis of the superior oblique muscle, in whom a recession of the ipsilateral inferior oblique was applied were enrolled in this study. These cases were selected among those with congenital superior oblique paralysis and infantile nontraumatic paralysis and those of unknown origin. Isolated recession of the inferior oblique muscle achieved a mean decrease in 8.69+/-2.05 D in hypertropia in the primary position. In 19 cases out of 23 (82.6%) who received, isolated recession of the inferior oblique muscle, a vertical deviation equal to or less than 4 PD was obtained, showing the efficacy of this method in the surgical treatment of the cases with superior oblique paralysis and a moderate inferior oblique hyperaction.