Children with reading disabilities (RD, n = 17), mathematical disabilities (MD, n = 22), combined reading and mathematical disabilities (RD + MD, n = 28) and control peers (n = 45) were tested on behavioral inhibition with a Go/no-go task in a picture, letter and digit-modality. In contrast to children without RD, children with RD made significantly more commission errors on alphanumeric (letter and digit) modalities compared to the non-alphanumeric picture modality. As compared to children without MD, children with MD made as much commission errors on the picture modality as on the letter modality. No significant interaction-effect was found between RD and MD. These results can be considered as evidence for behavioral inhibition deficits related to alphanumeric stimuli in children with RD but not in children with MD. (Contains 3 tables and 2 figures.)