A hybrid system is one whose response and the corresponding governing equations depend on the mode of operation. The system switches between its various modes of operation depending on certain transition conditions. It may so happen that certain parameters in the governing equations of such systems may be unknown and need to be estimated. In this article, we develop a scheme to estimate unknown parameters for a class of Single Input Single Output (SISO) linear hybrid systems. This scheme provides sufficient conditions for the parameter estimation error to be bounded and is illustrated with an example. © 2009 IEEE.