Background. An accurate method to assess albuminuria in pregnancy is mandatory to diagnose pre-eclampsia. Twenty-four-hour urine collection is still the only universally accepted method. This is, however, a cumbersome and inconvenient method. Therefore, the present study aimed at assessing the accuracy of a spot urine albumin/creatinine ratio in pregnant women with hypertension. Material and methods. In 54 pregnant women with blood pressure ≥140/90 mmHg, 24-h albumin excretion and subsequent albumin/creatinine ratio on morning spot urine were analyzed in the individual patients. Altogether 75 paired samples were included. Receiver operating characteristic curves, relating different albumin/creatinine ratio cut-off values to 24-h albumin excretion >300 mg were constructed. Correlations were assessed by Spearman rank correlation tests. Results. The area under the receiver operating characteristic curve was 0.985. At the optimal cut-off albumin/creatinine ratio value of 27 mg/mmol the sensitivity, specificity, positive and negative predictive value for detecting albuminuria >300 mg/24 h were: 95, 100, 100 and 86% respectively. There was a close correlation between albumin/creatinine ratio and 24-h albumin excretion values (r = 0.95; p<0.001). Conclusions. It is suggested that in most cases the more cumbersome 24-h urine collection can be replaced by the more convenient albumin/creatinine ratio on spot urine.