In a recent large series of tendon sheath syndrome, Brown reported only five cases of the pure acquired type that were not intermittent and in which the patients did not undergo spontaneous recovery. The origin of acquired Brown's syndrome is varied and includes trauma of the orbit, direct trochlear trauma, orbital or muscle surgery, frontal sinusitis or sinus surgery, and inflammation of the superior oblique tendon and sheath, namely a stenosing tenosynovitis. The differential diagnosis and possible causes of the acquired Brown's syndrome were reviewed, and two cases of presumptive tenosynovitis of the superior oblique tendon and sheath are presented in detail. In both cases, the condition of each patient was notably improved by a series of direct injections of methylprednisolone acetate into the trochlear region. This form of treatment for acquired Brown's syndrome of inflammatory origin has never, to my knowledge, been reported in the literature.