Purpose: The objective of this study was to identifiy if a low dose of BaP would alter gene expression profiles and key pathways in the liver and testis of adult male tilapia Methods: The liver and testis tissue from the BaP-treated or control groups fish were collected and then total RNA was extracted, RNA integrity (RIN) was evaluated (RIN >7) for Illumina RNA-Seq library construction and Sequencing. Gene read mapping was performed with TopHat and differential expression analysis (DE) was conducted using exact test with R package EdgeR (p < 0.05 fold change > ± 1.5 were considered as significant). Pathway analysis was performed using the gene set enrichment analysis (GSEA) and subnetwork enrichment analysis (SNEA) applying the Mann-Whitney test with an alpha level of p < 0.05 to identify the biological mechanism that underlie the BaP effects in male tilapia. Results: RNA-Seq analysis using EdgeR showed a larger number of altered genes in liver than in testis as a result of BaP exposure. In liver, 1444 genes were significantly differentially expressed, while in the testis only 309 showed any changes using a p < 0.05 and fold change > ± 1.5 Conclusions: Low dose of BaP can alter genes and molecular pathways in the liver and testis in male adult tilapia, and these changes could be associated with biological endpoints disruption. Overall design: Illumina NextSeq500 Sequencing was used to generate transcriptomic profiles for BaP-exposure liver (n=4 or control, n=4 for BaP) and testis (n=3 for control, n=3 for BaP) from adult male tilapia