Piglets are an important category in pig farming which should, alongside sows, be considered essential production heads. Over the past decades, the intensive selection in pig production has given priority to economically important traits resulting in greater feed utilization and obtaining more piglets from fewer sows. However, such selection practices have failed to improve the overall vitality of piglets and their ability to survive immediately after birth or during their stay in the farrowing unit. Body weight is of great importance in pig production, especially the piglet body weight at birth. A number of parameters can be predicted according to the piglet birth weight: mortality and growth rate, the physiological status of the heard, sensitivity to external influences, vitality and etc. The purpose of this paper is to determine the piglet body weight variation from birth to weaning (measured at birth, 3 hours after birth, 24 hours after birth and at weaning) and to examine the relationship between the birth weight of piglets and their body weight during the transition into nursing. A total of 105 piglets were enrolled in this study from the F1 generation sows followed through eight consecutive parities. The paper presents the results obtained using descriptive statistics, as well as variance and correlation analysis. The relationship between the piglet body weight at different stages of their life and overall production parameters was found to emphasize the centrality of housing conditions as the piglet weight at birth exerts a great impact on the body weight of older piglets, especially in the first days of the piglet life. Therefore, the proper care of piglets in farrowing units is of paramount importance to pig production, especially because piglets have lower body weight at birth nowadays than before.