The association between primary sclerosing cholangitis (PSC) and underlying inflammatory bowel disease (IBD) is well established. There are scant data on the association between non-IBD immunological diseases (NID) and PSC outcomes. Our objective was to investigate the impact of NID on the clinical outcomes in patients with PSC. We included 287 patients with PSC from 1985 to 2013 from our tertiary care data registry. Univariate and multivariate analyses were performed to assess the risk factors for liver transplantation. Of the 287 patients with PSC, 38 (13.2%) patients had at least 1 concomitant immunological disease other than IBD; 241 patients (84.0%) had concurrent IBD. The most frequent NIDs were autoimmune thyroiditis, autoimmune hepatitis, and rheumatoid arthritis. The median follow-up time did not differ significantly between PSC patients with and without NID (10.5 years versus 7.0 years, P = 0.04). We did not find significant difference in the median time from PSC diagnosis to liver transplantation between PSC patients with and without NID (5.2 versus 6.3 years, P = 0.74). In the subgroup analysis, there was no significant difference in the median time from PSC diagnosis to liver transplantation between the PSC-only group, PSC with IBD group, and PSC with NID group (5.4 versus 6.4 versus 5.2 years, P = 0.22). The association of NID in patients with PSC did not seem to affect the need for liver transplantation or transplantation-free survival. The findings suggest that the increased load of autoimmunity, including the presence of IBD or NID, has a minimum impact on the disease outcome of PSC.