In this article, the authors evaluate the role of sclerosing agents in dacryocystosclerotherapy (DCST) and aim to see whether it is an alternative to dacryocystectomy (DCT) in a specific group of patients. Thirteen lacrimal drainage systems of 10 patients with primary acquired nasolacrimal duct obstruction awaiting DCT were treated with either fluorescent labelled sodium tetradecyl sulphate (SDS) or bleomycin as sclerosing agent. The sclerosing agents were injected into the lacrimal sac very slowly and stopped immediately when there was regurgitation from the opposite punctum. The injection was repeated at one week if there was discharge or regurgitation. All patients underwent DCT after four weeks and histopathological evaluation was performed. The mean doses used for SDS and bleomycin were 0.26 and 0.31cc, respectively. Post-injection one patient developed moderate inflammation needing low dose of oral steroids. Histology post DCT in the SDS group showed loss of epithelium, near total or total luminal closure, severe inflammation, congestion and hyalinisation of blood vessels with perivasculitis, and gross fibrosis across the cell wall. The Bleomycin group showed severe epithelial oedema. Luminal epithelium was not lost but disorganised with focal areas of luminal synechiae. The inflammation and fibrosis were as severe as in SDS group but influence on sac wall vessels was less, suggesting SDS a better sclerosing agent.