A solid-state imaging device includes a photoelectric conversion section which is disposed on a semiconductor substrate and which photoelectrically converts incident light into signal charges, a pixel transistor section which is disposed on the semiconductor substrate and which converts signal charges read out from the photoelectric conversion section into a voltage, and an element isolation region which is disposed on the semiconductor substrate and which isolates the photoelectric conversion section from an active region in which the pixel transistor section is disposed. The pixel transistor section includes a plurality of transistors. Among the plurality of transistors, in at least one transistor in which the gate width direction of its gate electrode is oriented toward the photoelectric conversion section, at least a photoelectric conversion section side portion of the gate electrode is disposed within and on the active region with a gate insulating film therebetween.