The authors explored the possibility of assessing fetal lung maturity by measuring the phospholipids in the amniotic fluid by the enzymatic technique of Takayama et al. [8]. The study was conducted on 41 pregnancies. The results obtained were evaluated comparatively with the lecithin/sphingomyelin ratio (L/S). The authors found that the L/S ratio can be used to determine fetal lung maturity in 93% of cases with 2/14 false maturities and 1/27 false immaturities. The assay of the phospholipids containing choline by the method of Takayama et al. [8] gives a much less precise assessment of fetal lung maturity: only 68% of the results were concordant; 5/14 false maturities and 8/27 false immaturities. These differences can be explained by the fact that the method of Takayama et al. [8] takes into account substances which are not related to process of fetal lung maturation.