Piezoelectric layers have significant effect on the vibration behavior and buckling capacity of the structures. For optimum usage of piezoelectric materials, it is possible to use the piezoelectric patches instead of the piezoelectric layers. In this paper, the effects of piezoelectric patches and boundary conditions on the buckling and vibration behaviors of Euler-Bernoulli beams is investigated. The piezoelectric stress resultants are introduced in terms of Heaviside discontinuity functions and the characteristics equation is obtained via Galerkin method. The effects of variation of location, length of the piezoelectric patches and the applied voltages on the natural frequencies and critical buckling loads of beam with different boundary conditions are investigated. Results show that the natural frequencies and critical buckling load are dependent on the voltage, length and location of the piezoelectric patches and the axial load. Also, patches have a considerable effect if they placed at the beam center.