BACKGROUND The low specificity, together with the high intra- and interobserver variability, of cardiotocography (CTG) necessitates the use of additive fetal assessment methods. The German Society of Obstetrics and Gynaecology (DGGG) advises the use of computerised CTG analysis software systems. In this study we have examined the use of computerised CTG analysis together with the fetal pulse oximetry. METHODS Using the "CTG-Online ((R))" software five consecutive deliveries were simultaneously analysed by the FIGO score and the saturation rate of fetal pulse oximetry. All CTGs were classified as pathological and at least one fetal scalp pH measurement was carried out. Fetal outcome and results of the fetal scalp pH values were evaluated against the fetal pulse oximetry rates. RESULTS Signal loss was low at less than 5%. No fetus showed a hypoxic state. Only 0.98% of the fetal pulse oximetry saturation rates were below 30% oxygen saturation. No fetus showed an oxygen saturation of below 35% for 10 min duration or more. CONCLUSIONS Fetal pulse oximetry saturation rates can be another helpful marker for fetal well-being in a modern labour ward. Further studies are required to verify whether fetal pulse oximetry saturation rates can improve the specificity of CTG for fetal acidosis.