We present the results of a three-year campaign of broad-band photometry in the near-infrared J, H, K and L' bands for a sample of approximately 250 giant stars carried out at the Observatorio del Teide (Tenerife, Spain). Transformations of the Telescopio Carlos Sanchez system into/from several currently used infrared systems are extended to the redward part of the colour axis. The linearity of our photometric system in the range -3mag[Fe/H]>-3. Data of comparable quality previously published have been added to the sample in order to increase the reliability of the relations to be obtained. We also provide mean IR colours for giant stars according to spectral type. (3 data files). infrared stars measured at the Observatorio del Teide (Carlos Sanchez Telescope; TCS) during this programme of observations. Telescope (TCS) at the Observatorio del Teide. sensitivity of the InSb detector has been included.