We investigate the quantum coherence length, L, and mobility of conduction electrons in the dilute nitride alloy GaAs1−xNx. Analysis of the negative magnetoresistance using weak localization theory reveals a marked reduction in L with increasing N-content. Our data are compared to theoretical models of electronic transport in GaAs1−xNx and discussed in terms of the unusual type of compositional disorder exhibited by III-N-V alloys. A comparative study of the electron mobility in InAs1−xNx also indicates that disorder effects are significantly weaker in this small band gap material. ©2008 American Institute of Physics