The aim of this study was to assess the psychological state of women who have undergone surgery for breast cancer or cardiac surgery, including examination of the role of social support in both groups. The study included 48 women (mean age: 66.04 ± 8.3 years). They were divided into two groups according to diagnosis: 23 women (mean age: 69.2 ± 8.6 years) who underwent heart surgery (cardiac group, CG) and 25 women (mean age: 63.2 ± 7.0 years) treated for breast cancer and associated with the Women After Mastectomy Club (oncology group, OG). In addition to the assessment of socio-demographic variables, the following self-report questionnaires were administered: Satisfaction with Life Scale, Acceptance of Illness Scale, Beck Depression Inventory, Spielberger State-Trait Anxiety Inventory as well as Berlin Social Support Scale. In the CG, the severity of depressive symptoms was two times higher than in OG (p = .003). In both groups, there was a high percentage (80%) of women with severe symptoms of anxiety (p = .37). In both groups, the level of life satisfaction was similar (p = .58), but OG was characterized by a higher level of acceptance of the disease (p = .003). The correlation analysis showed that in both groups, social support was related differently to the parameters of emotional state. Women treated for breast cancer were in a better mental condition than women treated for heart disease. The support coming from other women in similar circumstances (Women After Mastectomy Club) seems to be more effective than the support coming from the patient’s immediate environment. The results for social support ought to be interpreted not only through the prism of mean values of received support, but also with regard to the information on the sources of support.