Trends in thick-film technology as applied in chemical sensor and biosensor fabrication are briefly reviewed and discussed. Current work aims at the production of sensor devices with a wide application range and commercial viability. Planar technologies are being employed for developing solid-state sensors having low cost, small size and high reproducibility. These technologies are compatible with silicon-based procedures that permit integration of the sensor and the associated electronic circuitry in the same chip. The use of planar technologies to produce sensors based on thick films can be very convenient since it calls for an inexpensive infrastructure, and is feasible for small to medium production runs. Once developed, a thick-film fabrication process can easily be combined with other planar technologies (chemical vapor deposition, plasma etching, etc.). The resulting devices can be produced in high volume at lower cost, with greater reproducibility and with further miniaturization.