This descriptive study attempts to identify the ways Registered Nurses (RNs) perform and interpret diabetic urine testing and capillary blood glucose monitoring measures. Seventy per cent of the RNs from one acute care hospital participated in the study. Seventy-six nurses participated; five of these comprising the pilot study. It was concluded that RNs did not perform these tests accurately according to standards. Knowledge of specimen collection procedures and drugs which affect urine testing results was not consistently high. RNs perceived the definitions of hypoglycaemia, normoglycaemia and hyperglycaemia more widely than standard ranges thus having major implications for patient care. RNs'experience with tests is not necessarily related to the accurate completion of the tests. Implications, limitations and idiosyncracies of each test should be taught in addition to procedural specifics so that nurses can make sound judgements for patient care.