Objective To observe the influence of disease uncertainty ( DU) to patients' compliance with rehabilitation training ( CWRT) , shoulder joint movement (SJM) , and abilities in activities of daily living ( ADL) in post-operative breast cancer (BCPO) patients. Methods Sixty-seven BCPO patients uncertain about their health was assessed using Missals' DU protocol. They were then treated according to the breast cancer rehabilitation training plan recommended by the Japanese Cancer Association. CWRT, SJM and ADL were evaluated before and after treatment. Results The scores on dependency of recovery training, systematic remedy and the ability to change their life style were distinctly higher among patients with low DU scores than among those with high DU scores. The shoulder joint mobility in two groups was similar before the remedy, but became better after treatment. ADL category grades and ADL total scores in the two groups were similar before treatment, and had increased significantly after treatment. The item scores for defecating, diet, dressing and bathing, as well as ADL total scores, were significantly lower in the high uncertainty group. Conclusion DU is one of most important factors for BCPO patients. It can influence CWRT and therapeutic effects in rehabilitation.