Orthograde and retrograde endoscopy of the upper and lower nasolacrimal system was performed using two prototype ultrathin (0.5 mm and 1.1 mm diameter) fibrescopes on four cadaver heads. Appearances were verified by subsequent dissection. The procedure, which we term 'dacryocystoscopy' is described. With modifications this technique may have clinical applications in the treatment of nasolacrimal disorders.