Photo-response of solution processed flexible TIPS-pentacene organic field-effect transistors is evaluated under illumination with visible light of red, green, and blue colors having minimum wavelengths of 620, 520, and 460 nm. For - 10 V operation, pristine photo-OFETs exhibited average field-effect mobility of 0.11 cm V s, near zero threshold voltage, and current ON-OFF ratio of ∼10. These photo-OFETs exhibited prevalent photovoltaic characteristics with shift in the threshold voltage upon illumination, which was found to increase with rising intensity, illumination time, and gate bias during illumination. For low-voltage operation at - 5 V, maximum current modulation of 4 × 10 and 10, and photo-responsivity of 17 mA/W and 35 mA/W, respectively, were achieved for blue (intensity of 1.7 mW/cm) and green (intensity of 0.4 mW/cm) light illuminations. However, these photo-OFETs did not show significant response to red light. A fast dynamic response to periodic pulses of illumination was also observed. For a gate bias of +10 V and illumination time of 500 s, maximum current modulation of 10 was achieved for blue light illumination. © 2017 IEEE.