We compared the effect of Argon Laser trabeculoplasty (ALT) and Nd-YAG-Laser trabeculoplasty (YLT) on inflammation and intraocular pressure (IOP). Twenty-two patients scheduled for bilateral trabeculoplasty were treated with an Argon laser in one eye and with Nd-YAG laser in the controlateral eye. Visual acuity, IOP and anterior chamber inflammation (measured with the laser flare-cell meter) were controlled at 0, 3, 6, 18 hours, 2, 4, 7, 14, 30, 90 and 180 days after trabeculoplasty. Our results showed a similar pressure lowering effect in both groups (-24.5 +/- 23% after YLT versus -32.9 +/- 16.3% after ALT at 90 days post-laser; p = 0.26). The anterior chamber inflammation was delayed and more important in the ALT-group (inflammation peaked at 24.8 hours after YLT versus 44.5 hours after ALT; p = 0.034) (maximal mean flare increase: 19.4 +/- 12 pH/msec. after ALT, versus 16.1 +/- 11.4 ph/msec. after YLT). All eyes with inflammation were successfully treated with topical diclofenac QID (Voltaren Ophtha), a nonsteroidal anti-inflammatory agent. YLT is a safe and effective alternative technique to perform laser trabeculoplasty, which is especially useful in poorly pigmented angles where ALT is known to be less effective.