An image sensor package includes a first substrate, an image sensor chip, a processing chip and a plurality of passive elements. The first substrate has a supporting surface and a bottom surface opposite to the supporting surface. The image sensor chip is disposed on the supporting surface and electrically connected to the first substrate. The image sensor chip package further includes a second substrate. The processing chip and the passive elements are mounted on the second substrate and electrically connected to the second substrate. The bottom surface of the first substrate defines a cavity for receiving the second substrate, the processing chip and the passive elements therein.