According to the European and national legislation which set the minimum standards for pig protection, the castration of piglets after the age of seven days must be performed only under prolonged anaesthesia and analgesia. As far as welfare is concerned, pig castration in these conditions is mandatory in order to reduce to the minimum the pain generated by the surgical method itself. Immunocastration is an alternative methods to surgical castration based on the use of antibodies against the gonadotropin releasing hormone (Gn-RH), which once neutralized suppresses testicles development and function and inhibits the smell of boar. The aims of this study were to see the immunocastration effects on productive performance in pigs PIC hybrids. Animals included in the study were PIC fattening pigs, grouped in two groups: A lot (n: 485) - surgically castrated pigs, and B lot (n: 604) - immunocastrated pigs. The fattening technology was identical for all pigs included in this study. Pigs’ immunization was performed using Improvac®. The results obtained showed that A lot recorded a daily average weight gain of 785 g, while loss due to mortality was 2.82 %. In the case of lot B, the recorded daily average weight gain was 834 g (49g higher than the one in lot A), while loss due to mortality were 2.59 % (0.23 % lower than in lot A). Pig immunocastration is an acceptable method as far as welfare standards are concerned, reducing the stress generated by surgical castration. Productive performance in immunocastrated pigs are improved compared to the one of surgically castrated pigs.