Background: Breast cancer is one of the most common tumours and one of the leading causes of death among women in all parts of the world. The aim of this study is to investigate the influence of Nordic walking on the functional capacity of women who have undergone surgery for breast cancer. Methods: The study involved a cohort of women who exercised through Nordic walking for 10 weeks (from March to May 2022). The subjects trained with a licenced instructor (INWA method), with two training sessions per week of 70–80 min each. We collected information on pain, arm mobility, hand grip strength, shoulder joint range of motion bilaterally, circumference of both arms, body mass index, physical activity, aerobic capacity, and endurance. Results: There were 14 women, median age 63. BMI was significantly lower (28.9/28.1; p = 0.013) after training and a difference in shoulder range of motion was better (anteflexion right (142.5/170, p = 0.002), retroflexion right (40/60, p = 0.005), abduction right (135/180, p = 0.005), abduction left (135/180, p = 0.005)). There was no difference in right hand strength, while there was a significant difference in left hand strength (19/20, p = 0.007). A correlation was found between BMI and the six-minute walk test (r = −0.70; p = 0.005). Conclusions: Considering the multidimensionality of the disease itself and the results of this study, we believe that Nordic walking is a favourable and good choice of physical activity for breast cancer patients.