The objective of this study was to identify the clinical characteristics of Clostridium difficile infections (CDIs) caused by toxin A-negative/toxin B-positive (A-B+) PCR ribotype 017 (R017) and A+B+ ribotype 018 (R018) strains, prevalent in Asian countries. From February 2010 through January 2013, all CDI patients in our hospital were enrolled; their medical records were retrospectively reviewed, and the isolates were characterized by toxigenic culture and PCR ribotyping. Based on the ribotypes, a total of 510 cases were categorized as R017 (139, 27.3%), R018 (157, 30.8%) and other ribotypes groups (214, 42.0%), and clinical variables were compared between R017 and other ribotypes, R018 and other ribotypes and R018 and R017 groups. The patients with R017 infections had a higher mean Charlson's comorbidity index (OR 1.1, 1-1.21, p = 0.05), lower serum albumin (OR 0.47, 0.31-0.73, p = 0.001) and lower CRP levels (OR 0.96, 0.92-0.99, p = 0.022) than those with other ribotypes. R018 infections caused more azotemia (OR 4.06, 1.28-12.91, p = 0.018) and more frequent severe CDI (OR 1.87, 1.12-3.13, p = 0.016) than the other ribotypes infections. R017 and R018 infections were more often associated with toxin positive stools (OR 2.94, 1.65-4.09, p<0.001; OR 4.55, 2.82-7.33, p<0.001). In terms of treatment outcomes, R017 infections caused a marginally higher 30-day mortality than other ribotypes infection. In a final multiple logistic regression model, 30-day mortality was associated with leukocytosis (OR 2.45, 1.0-6.01, p = 0.05) and hypoalbuminemia (OR 4.57, 1.83-11.39, p = 0.001), but only marginally with R017 infection (OR 2.14, 0.88-5.22, p = 0.094). In conclusion, infections by C. difficile R018 strains tend to cause more severe disease, while there was a trend for higher mortality with R017 infections.