Purpose To compare the clinical outcomes of two treatment approaches for bilateral nasolacrimal duct obstruction (NLDO) in infancy. Design Multicenter, randomized clinical trial. Methods We studied 57 infants between the ages of 6 and <10 months who had bilateral NLDO. Participants were randomized to receive either (1) immediate office-based probing within two weeks (n = 31) or (2) 6 months of observation and nonsurgical management followed by surgical facility-based probing for unresolved cases (n = 26). Treatment success was defined as the absence of clinical signs of NLDO (epiphora, increased tear lake, mucous discharge) in both eyes on masked examination at 18 months of age. Results In the observation and deferred facility probing group, resolution without surgery occurred by 6 months after randomization in both eyes for 14 participants (56%), in one eye for 5 (20%), and in neither eye for 6 (24%). Eight participants in the observation and deferred facility probing group underwent facility probing (one of whom later had a second facility probing). Four participants in the immediate office probing group later underwent an additional procedure in a surgical facility. In the immediate office probing group, treatment success at 18 months of age occurred in both eyes for 19 of 29 (66%) participants and in one eye for 3 (10%); in the observation and deferred facility probing group, treatment success occurred in both eyes for 19 of 25 (76%) participants and in one eye for 3 (12%) (difference in success = -10%; 95% CI = -35% to 14%). Conclusions Both the immediate office probing approach and the observation and deferred facility probing approach are successful and reasonable treatment options for infants with bilateral NLDO.