Polycyclic aromatic hydrocarbons (PAHs) in sediment and edible fish (Megalops atlanticus) from Caleta lagoon (Terminos Lagoon, Campeche, Mexico) were quantified to evaluate the toxicity and bioaccumulation factor (BAF) and biota-sediment accumulation factor (BSAF). A total of 15 sampling stations were placed in three strata (zone I, II and III) along the Caleta lagoon. The intermediate part (zone II) showed higher concentration of PAHs of low molecular weight (LMW) (223.96 ng g^-1 dw), while zones I and III showed higher concentrations of PAHs of high molecular weight (HMW) (629.6 ng g^-1 dw and 319.12 ng g^-1 dw, respectively), suggesting petrogenic and pyrolytic sources. The high concentration of LHW PAHs (190.3 ng g^-1 dwt) in fish tissue indicated a greater availability from the water column. The toxic (TEQ) and mutagenic (MEQ) equivalent quotients and the effects of range-median (ERM) values showed a sediment with low probability of toxicity, while the BAF and BSAF values suggest a high bioavailability of PAHs from the exchange zones between the ocean and urban wastewater.