This study investigates the effects of stress, dyadic communication and dyadic adaptation of patients who received prostatectomy and their spouses on the quality of life (QOL) of patients. A descriptive design was used with 113 prostatectomy couples. Data were collected from December 2012 to February 2014 at a prostate cancer centre in Korea. Stress, dyadic communication, dyadic adaptation and patient QOL were measured with the perceived stress scale, communication pattern questionnaire, Revised Dyadic Adjustment Scale and Functional Assessment of Cancer Treatment-Prostate, respectively. Emotional QOL of patients was negatively affected by stress ( = −0·624, p < 0·001) and mutual avoidance communication ( = −0·050, p = 0·001) of the patients as well as couple cohesion ( = −0·113, p = 0·015). The predictive power (F = 25·895, p < 0·001) was 41·6%. Social QOL of patients was negatively affected by patient stress ( = −0·331, p = 0·010) and positively affected by the constructive communication of the patients ( = 0·034, p = 0·006) and spouses ( = 0·029, p = 0·014) and withdrawal communication of the spouses ( = 0·035, p < 0·001), and the predictive power (F = 11·391, p < 0·001) was 29·7%. Functional QOL of patients was negatively affected by patient stress ( = −0·680, p < 0·001) and positively affected by the patients' assessment of couple cohesion n ( = 0·173, p = 0·007). The predictive power (F = 18·491, p < 0·001) was 25·2%. To improve the QOL of patients who received prostatectomy, a programme needs to be developed to reduce patient stress and improve constructive communication and couple cohesion.