Uncertainty exists regarding safety and efficacy of dual biological therapy (DBT) in inflammatory bowel disease. We present four cases of DBT in Crohn's disease. Three patients had refractory disease non-responsive to biological monotherapy or combination therapy with immunomodulators. One patient had concomitant ankylosing spondylitis. DBT was implemented by combining vedolizumab with an anti tumour necrosis antibody or with ustekinumab. DBT was well-tolerated, though two patients did experience self-limited infections. The efficacy of DBT remains unproven but it appears promising as three of the four patients achieved clinical remission. Our case series contributes insight into the safety of DBT that incorporates vedolizumab for future efficacy studies.