Inorganic semiconductor metal-semiconductor transistors were developed more than 40 years ago. However, despite being potentially attractive for fast switching and sensor applications, they are difficult to produce and usually show low base transport factors, thereby limiting their applicability. Recent developments in hybrid organic/inorganic semiconductor-metal-semiconductor transistors, however, demonstrate that high-gain transistors can be produced using simple technologies. Additionally, their fabrication is compatible with well established silicon electronics technology, which provides an enormous advantage. These devices, built in a vertical architecture, Offer attractive new possibilities due to the large variety of available molecular, semiconductors, opening the possibility of incorporating new, functionalities in silicon-based devices.