Recently, Sevag & Colton (1959) published a chemical test for detecting the precise day of ovulation. We have performed this test in 112 menstrual cycles of sixty women. Out of 112 menstrual cycles studied, in fifty-six menstrual cycles (50%) the chemical patterns were atypical. We do not substantiate the claim of Sevag & Colton that the ovulation invariably occurs between 10th and 14th days of menstrual cycle. This test needs further confirmation from other tests such as endometrial biopsy carried out simultaneously.