To analyze the clinical characteristics and prognosis of patients with primary aldosteronism (PA) associated with subclinical Cushing syndrome (SCS). This retrospective cohort study was conducted at the First Affiliated Hospital of Chongqing Medical University in China. Patients with PA were included between January 2014 and December 2022. According to the results of 1-mg overnight dexamethasone suppression test, the patients were divided into the PA group and PA associated with SCS (PA/SCS) group. The demographic information, hormone levels, and follow-up results were analyzed. Independent sample -test, chi-square test and Mann-Whitney test were used for data comparison. A total of 489 PA patients were enrolled in this study, of which 109 had PA/SCS (22.3%). Patients with SCS were on average older (54.4±10.7 vs 47.4±11.0, <0.001); had a larger proportion of women (69.7%, 76/109 vs 57.4%, 218/380; =0.020); and a longer duration of hypertension [96 (36, 180) vs 60 (12, 120) months, =0.001] than patients without SCS. There were 215 and 51 patients in the PA group and PA/SCS group, who completed adrenalectomy and follow-up, respectively. The remission rate of autonomous cortisol secretion in the PA/SCS group was 85.3% (29/34). There was no significant difference in the remission rate of autonomous aldosterone secretion among patients between the PA/SCS and PA group (94.1%, 48/51 vs. 94.4%, 203/215; =1.000), while the clinical remission rate in the PA/SCS group was lower than that in the PA group (39.2%, 20/51 vs. 61.9%, 133/215; =0.003). SCS is common in PA patients (22.3%), and the clinical remission rate is low. Screening using the 1-mg overnight dexamethasone suppression test is recommended for all patients with PA.