Electronic quantum transport is investigated in boron- and nitrogen-doped carbon nanotubes using tight-binding methods correlated to ab initio calculations. The present technique accurately accounts for both effects of dopants, namely, charge transfer and elastic scattering. Generic transport properties such as conduction mechanisms, mean-free paths, and conductance scalings are derived for various concentration of randomly distributed boron and nitrogen dopants. Our calculations allow direct comparison with experiments and demonstrate that a small amount of dopants (<0.5%) can drastically modify the electronic transport properties of the tube, which is certainly a key effect feature for envisioning nanoelectronics.