A method for dynamically invoking a Web service. The method can include assembling a collection of references to remote implementations of the Web service based upon a common port type. One or more ports bound to the remote implementations of the Web service can be identified, and a set of port selection rules can be applied to the identified ports to select a particular one of the ports. Finally, the Web service can be invoked through the selected port. Notably, the identifying step can include parsing a Web service implementation document for each referenced remote implementation in the collection. The parsing can produce a list of ports through which the remote implementations can be invoked. Also, the method can further include compiling the set of port selection rules according to at least one of high-availability concerns, quality of service concerns and economic concerns.