We have obtained uvby and JHK photometry of about 80 stars in the association Cygnus OB2 (VI Cygni), including some foreground stars and three infrared sources. We present colour–colour and colour–magnitude diagrams from which we derive the interstellar extinction and approximate spectral types. We confirm that the interstellar extinction law in the direction of Cyg OB2 is similar to the galactic mean. The ratio of total-to-selective extinction is found to be |$R_{V}= 3.04 \pm 0.09.$| We derive a true distance modulus of |$V_{0} - M_{V} = 11.2 \pm 0.2,$| corresponding to |$d=1.7\pm0.2$| kpc. The majority of the stars are still on the main sequence; we estimate a minimum age of 3 Myr for the association. Only two stars in our sample show significant infrared excesses at |$\lambda \geq 2.2 \mu \text{m}.$|