A total of 192 Iberian female pigs (Duroc x Iberian), with 110 days old and 44.94 ± 3.41 kg, were used to test the effect of immunological castration Improvac ® (Pfizer Animal Health). The trial was conducted at the Centro de Pruebas de Porcino of Instituto Tecnológico Agrario de Castilla y Léon in Segovia (Spain) The experiment was designed in randomized blocks, with 3 treatments (surgically castrated, entire female and inmunocastrated), 48 total replicates of 4 pigs each and 16 replicates per treatment. The animals were weighed individually every 15 days and it was estimated feed intake, weight gain and feed conversion. Once applied the two doses of Improvac® (60 kg and 84.2 kg) of body weight, differences between entire females and inmunocastrated became statistically significant (P < 0.05) over 100 kg, remaining the significance to 170 kg, showing the latest higher feed intake, average daily gain and feed conversion ratio (21.25, 19.24 and 1.44%, respectively; P < 0.05). In relation to castrated and after application of the second dose, inmunocastrated increased feed intake (12% on average, depending on the weight considered) and daily gain (22.24%), decreasing by 7.6% feed conversion ratio (P < 0.05). On the other hand, castrated feed intake is higher (8.35%), with lower daily gain (2.6%) and higher feed conversion ratio (11%) than the entire females (P < 0.05). At slaughter, the entire females showed lower carcass yield (78.02 vs. 79.14 and 78.79% for entires, castrated and inmunocastrated respectively, P < 0.05). By contrast, the weight of prime cuts parts was higher in the entire and inmunocastrated (P < 0.05). Under the our conditions, we can conclude that the immunocastration is a productive alternative advantageous to physical castration in Iberian females, recommending a separation of 10 ± 2 weeks between the application of the second dose of Improvac ® and sacrifice to obtain the maximum benefit, and also with the same pattern of application, has a more favorable conversion to commercial slaughter weights in relation to entire female. Surgical castration is the least interesting option.