The piglet birth weight and its variance within a litter may be considered important traits that influence pig productivity in the first and later stages of rearing. 222 piglets were evaluated from the moment they were born until weaning, and then as fattening pigs until the end of the fattening (n = 207) in three birth weight groups. Negative consequences of an excessively low piglet birth weight were observed, including higher mortality until weaning and a lower average daily gain during suckling. The correlation coefficients between the piglet birth weight and the remaining indicators confirmed the negative impact of the low piglet birth weight, fattening performance and carcass slaughter value (P