Nitrogen- heterocyclic polycyclic aromatic hydrocarbons (N-PAHs) are ubiquitous constituents of contaminated sites in which their high water solubility and lower kow values imply greater mobility and impacts. Biodegradation is a major route of loss for organic contaminants in soil. In this study, microbial degradation was investigated in soil artificially contaminated with N-PAHs and monitored for over 200 days. The results showed that all the aromatic chemicals exhibited loss with increasing incubation time; however, only 0.05 ± 0.04 mg kg day−1 loss was observed for N-PAHs at 10 mg kg−1 amendments over the first 30 days incubation, with the exception of 4,7-phenanthroline which recorded 0.19 ± 0.03 mg kg day−1. The study showed that soil microflora have the potential to degrade N-PAHs since all of the aromatics recorded chemical losses under aerobic condition. However, degradation rates varied between chemicals and this was attributed to N-atom position and/or number of N-substituents. Further, relatively little or no biodegradation was observed in B[h]Q amended soils with increasing concentration; indicating that B[h]Q is more resistance to biodegradation in soil.