Infrared photometry in the J, H and K bands, performed on a sample of 33 blue stragglers (BS) belonging to 8 open clusters is presented. This photometry has been combined with published Johnson UBV photometry to search for possible cold companions among the BS, as expected for Case B close binary evolution. Probable binaries were identified by comparison with standard mean color relations for single stars. The number of binary detections is discussed together with the results of a previous spectroscopic search for binaries among BS (Manteiga et al. 1989), and the consequences for the hypothesis of binarity for the origin of BS are analyzed.