A free shoulder exercise for individuals after breast cancer surgery has been used in a hospital. The exercise has no warm-up and cool-down and research evidence. The exercise should be adjusted to a certain designed progressive shoulder exercise that was expected to use instead of the previous one. The study aimed to compare the effect of the certain designed progressive with the free shoulder exercise on shoulder range of motion, shoulder and arm function, net amount of seroma, pain, and overall satisfaction. Sixty (n = 60) individuals after breast cancer surgery were randomized to the free (n = 30) and certain designed progressive shoulder exercise group (n = 30). Both groups exercised by themselves using booklet and video. The free shoulder exercise group chose and did exercise as they preferred, whereas the certain designed progressive shoulder exercise group followed the exercise as described. Both groups were assessed for active and passive shoulder range of motion in all directions, shoulder and arm function, total seroma excretion, pain, and overall satisfaction. The certain designed progressive shoulder exercise showed similar outcomes to the free shoulder exercise, except less active (p-value = 0.014) and passive (p-value = 0.012) shoulder flexion range on day 3 after surgery. The certain designed progressive shoulder exercise was inferior to the free shoulder exercise on shoulder flexion range on day 3 after surgery. However, its final effect was comparable to the free shoulder exercise. The certain designed progressive shoulder exercise is suggested to be a shoulder exercise after breast cancer surgery since it demonstrates a particular exercise poses and frequency and no pain after exercise.