Purpose. To compareab internoandab externoscleral fixation of posterior chamber intraocular lenses (PCIOL) using ultrasound biomicroscopy (UBM).Methods. Randomized patients underwentab externoorab internoscleral fixation of a PCIOL. Ultrasound biomicroscopy was performed 3 to 6 months postoperatively, to determine PCIOL centration, IOL distance to the iris at 12, 3, 6, and 9 hours, and haptics placement in relation to the ciliary sulcus.Results. Fifteen patients were enrolled in the study. Theab externotechnique was used in 7 eyes (46.6%) and theab internoin 8 eyes (53.3%). In theab externotechnique, 14 haptics were located: 4 (28.57%) in the ciliary sulcus; 2 (14.28%) anterior to the sulcus; and 8 (57.14%) posterior to the sulcus, 6 in the ciliary body and 2 posterior to the ciliary body. In theab internogroup, 4 haptics (25.0%) were in the ciliary sulcus, 2 (12.50%) anterior to the sulcus, and 10 (75.0%) posterior to the sulcus, 4 in the ciliary body and 6 posterior to the ciliary body.Conclusions.Ab externoandab internoscleral fixation techniques presented similar results in haptic placement.Ab externotechnique presented higher vertical tilt when compared to theab interno.