A prospective study was undertaken to assess whether the level of intraocular pressure (IOP) on the first day after cataract surgery could be estimated by clinical examination only, thereby removing the need for applanation tonometry. A total of 70 patients underwent uncomplicated extracapsular cataract extraction and intraocular lens implantation. The following day a Consultant, Registrar and Senior House Officer were asked to identify those patients with significantly raised IOP (> 27 mmHg) using slit lamp examination only. A fourth examiner, masked to the assessments of the three observers, measured the IOP using the Goldmann applanation tonometer. Pressures of > 27 mmHg by Goldmann tonometry were found in 10 patients (14%) of which 8 (80%) were missed by all three ophthalmologists. Formal measurement of IOP appears a necessary part of the post-operative assessment after uncomplicated cataract surgery.