In a prospective study, the efficacy of argon laser trabeculoplasty (ALT) was evaluated and compared with pilocarpine 2% as primary treatment in newly diagnosed primary open angle glaucoma (POAG). Out of 38 patients with POAG included in this study, one eye each of 36 patients underwent ALT, and one eye each of 26 patients received pilocarpine 2% every 8 hours. The mean pre-treatment IOP was 25.48 +/- 4.13 mmHg in ALT group and 24.47 +/- 3.51 mmHg in the pilocarpine group. The mean post treatment IOP at 2 year follow was 18.2 +/- 2.55 mmHg in ALT group and 18.27 +/- 2.22 mmHg in the pilocarpine group. Post treatment IOP was significantly lower than pre-treatment IOP in both ALT and pilocarpine groups. The post treatment fall in IOP showed no significant difference in ALT versus pilocarpine 2% at various follow up intervals (p > 0.05). This study showed equal efficacy of ALT and pilocarpine 2% as initial therapy of POAG.