Surgical drains and methods for using the same for draining a body cavity are provided. Aspects of the surgical drains of the invention include an elongated structure having a proximal end and a distal end and a lumen configured to drain a substance from the body cavity. The distal end is configured to be placed in a body cavity and change in diameter when present in the body cavity from a first diameter to a second diameter that is smaller than the first diameter, where the change in diameter is mediated by a diameter-varying element. Aspects of the invention further include sheaths configured to be disposed around surgical drains, such as surgical drains of the invention, and methods of using the surgical drains and sheaths. The devices and methods of the invention find use in a variety of applications.