Undetermined coefficients method is presented for nonhomogeneous sequential fractional differential equations involving Caputo fractional derivative of order n\alpha where n-1 n\alpha\le\ n and n\in\mathbb{N}. By employing presented method, a particular solution of the considered equation is obtained. Some details about the estimation of the particular solution required to apply this method are explained. It is shown that this method is particularly effective for nonhomegenous fractional differential equations when the fractional differential equations involve some specific right-hand side functions.