The clinical records of 14 patients with posterior scleritis were reviewed to compare the diagnostic potential of computed tomography (CT) and magnetic resonance imaging (MRI) in this condition. None of these patients had evidence of collagen vascular or other systemic diseases. Done 13 times on 11 patients, CT was diagnostic for posterior scleritis in six patients on seven occasions. We used MRI six times in five patients, and it was not diagnostic for posterior scleritis in any patient. Thus, CT appeared to be more sensitive than MRI in the diagnosis of posterior scleritis. The CT results appeared comparable to ultrasonographic findings (obtained eight times in six patients) in the diagnosis of posterior scleritis. Both CT and MRI, however, detected signs of orbital pseudotumor in six and three patients, respectively. These findings support the concept that posterior scleritis and orbital pseudotumor may represent a continuum of the same disease process.