792 urine samples from pregnant patients were investigated by a direct latex agglutination test (LA). Results of this slide test were compared with data derived from a haemagglutination inhibition test (HI). The same results were obtained by both pregnancy tests in 768 (96.7%) out of 792 urine samples. The pregnancy test was negative in 20 cases (2.5%) as assessed by HI, whereas a positive result was recorded with the LA in these cases. Seven were cases of early pregnancy and control tests performed by HI became positive at a later date. The remaining 13 (1.6%) of these patients belonged to a group of pathological pregnancies (missed abortion, threatened abortion, incomplete abortion and ectopic pregnancy). The slide test is more sensitive (1000 I.U. HCG/1 urine) than the HI (1500 I.U.HCG/1 urine). No false positive results were obtained with the LA; false negative results were registered in only 0.5% of cases. A semi-quantitative HCG determination was performed by means of the tube and slide test in 29 urine samples. However, agreement of the data by the two methods was relatively poor, owing to the higher sensitivity of the LA, with consequent inaccurate assessment of HCG excretion. Not much importance need be attached to this finding in view of the diagnostic and prognostic deficiencies of HCG determination. The new slide test was found to be a rapid, simple and accurate pregnancy test.