We have obtained CCD UBVI_KC_ photometry down to V~21.0 for the open clusters Berkeley 26, Czernik 27, Melotte 72, NGC 2479 and BH 37. The latter has never been studied before. Cluster stellar density profiles were obtained from star counts in appropriate-sized boxes distributed throughout the entire observed fields. Based on different measured indices, we estimate the ages of Berkeley 26, Melotte 72 and NGC 2479. On the other hand, we indicate possible solutions for the cluster fundamental parameters by matching theoretical isochrones which reasonably reproduce the main cluster features in their colour-magnitude diagrams. In the case of NGC 2479, the cluster E(BV) and E(VI) colour excesses and apparent distance modulus were estimated from the fit of the zero-age main sequence to the colour-colour and colour-magnitude diagrams, respectively.