This case study attempts to determine the effect of a hydrokinesitherapy program by means of the Halliwick method on physical fitness in a female aged 35 years with poliomyelitis sequelae. The intervention followed sixteen weeks of hydrokinesitherapy during 70 minutes, five times a week, where we carried out exercises from the Halliwick method. There was an assessment both before and after the application. Strength endurance and flexibility were determined according to a senior fitness test protocol. The results showed positive improvements when carrying out the exercises from the Halliwick method and the percentage change (Δ%) of strength endurance increase 361.5% in the right arm and 300% in the left arm. Flexibility increased 2 cm in the right shoulder and 10 cm in the left shoulder. In conclusion the subject was able to improve the performance of Halliwick exercises while showing an increase in strength endurance and flexibility