Background Many difficulties exist in establishing a treatment plan for slow-flow vascular malformation (SFVM). In particular, little research has been conducted on the surgical treatment of SFVMs. Thus, we investigated what proportion of SFVM patients were candidates for surgical treatment in clinical practice and how useful surgical treatment was in those patients. Methods This study included 109 SFVM patients who received care at the authors’ clinic from 2007 to 2015. We classified the patients as operable or non-operable, and analyzed whether the operability and the extent of the excision varied according to the subtype and location of the SFVM. Additionally, we investigated complications and self-assessed satisfaction scores. Results Of the 109 SFVM patients, 59 (54%) were operable, while 50 (46%) were nonoperable. Total excision could be performed in 44% of the operable SFVM patients. Lymphatic malformations were frequently non-operable, while capillary malformations were relatively operable (P=0.042). Total excision of venous malformations could generally be performed, while lymphatic malformations and combined vascular malformations generally could only undergo partial excision (P=0.048). Complications occurred in 11% of the SFVM patients who underwent surgery; these were minor complications, except for 1 case. The average overall satisfaction score was 4.19 out of 5. Conclusions Based on many years of experience, we found that approximately half (54%) of SFVM patients were able to undergo surgery, and around half (44%) of those patients were able to fully recover after a total excision. Among the patients who underwent surgical treatment, high satisfaction was found overall and relatively few complications were reported.