PURPOSE: To compare corneal endothelial cell loss after cataract surgery by phacoemulsification and by Aqualase. METHODS: This was a prospective, randomized study of 75 eyes of 75 patients undergoing cataract surgery. Patients were randomly assigned to receive either phacoemulsification or Aqualase for cataract removal. Specular microscopy was used to calculate endothelial cell counts preoperatively and 3 weeks and 6 months afterwards. Best-corrected visual acuity was also measured. The t-test was used to detect statistical significance. RESULTS: The mean endothelial cell loss was 8.1% in the phacoemulsification group and 6.8% in the Aqualase group. There was no statistically significant difference in the amount of endothelial cell loss or in visual outcome between the 2 groups. The number of Aqualase pulses tended to increase with nuclear density while the phacoemulsification time showed little variation with nuclear subtype. CONCLUSION: Endothelial cell loss after cataract surgery is similar whether phacoemulsification or Aqualase is used. Aqualase can be considered to be as safe as phacoemulsification with regard to corneal trauma and is a useful alternative especially for soft cataracts.