Twenty-four Polish Landrace pigs were fed a standard, complete pelleted diet with free access to water. All of the animals were slaughtered at 108 kg BW and their blood was sampled. During dissection, samples of M. longissimus dorsi (LD) were taken. Serum leptin concentrations were determined by a radioimmunoassay, and the physicochemical and sensory traits of the meat were assayed. The results were categorized into groups with low (<3 ng/ml) or high (>5 ng/ml) leptin concentrations. The serum concentration of leptin had no effect on fattening performance or carcass quality. The animals with a higher leptin concentration showed 1% better meatiness, as reflected in the higher content of ham. No differences in the physicochemical or sensory characteristics of meat were found.