Pyoderma gangrenosum (PG) is an ulcerative skin disorder characterized by neutrophilic infiltrations. PG is generally classified into four types: (i) ulcerative; (ii) pustular; (iii) bullous; and (iv) vegetative. Among them, bullous PG is known as a rare type. Herein, we report a case of bullous PG together with a summary of the 12 PG cases treated in our department over the previous 15 years, and we review 38 well-documented bullous PG cases (65.8% female; aged 18–80 years [mean ± standard deviation, 51.6 ± 16.8]) in the published work, including the present case, from 1972–2011. Although the disease most frequently associated with PG is inflammatory bowel disease, bullous PG is most commonly associated with hematological disorders (25/38, 65.8%), which indicates the characteristic pathophysiology specific to bullous PG.