Predicting the parturition date in dogs by taking ultrasonographic foetometry has opened interesting research areas of veterinary obstetrics. Recently developed calculation formulas of inner chorionic cavity diameter (ICC) and biparietal diameter (BP) are formulas by Luvoni and Grioni (2000). This study is one of the first reports referring to ICC and BP with the use of Luvoni and Grioni formulas for predicting the parturition time in dogs of different body weight in clinical practice conditions. The research material consists of 70 clinically healthy pregnant bitches of 27 breeds and cross-breeds. Bitches were divided into 4 groups according to their body weight. In each of the bitches, ultrasonographic examination of pregnancy was performed at least twice (ICC and BP measurements). Parturition dates for dogs with a body weight over 25 kg were calculated based on formulas intended for the group of medium dogs. It was caused by the lack of appropriate formulas for these groups of dogs. The predicting parturition dates were compared with the actual dates of delivery provided by the bitch owners. Generally, the results obtained in this study are very encouraging and similar or even better than those published by other authors using foetometric measurements. In our research, when comparing the effectiveness of predicting the delivery date based on foetometric formulas by Luvoni and Grioni (2000), it was proved that in all groups of dogs, even those over 25 kg, ICC and BP measurements at both accuracy levels were characterized similar reliability.