Sediment and mussel tissues from the Kentucky Dam Tailwater (KDTW) and Ledbetter Embayment (LE) of Kentucky Lake, Kentucky, USA, were analyzed to examine the presence of 2,3,7,8-substituted polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and non-, mono-, and di-ortho-chlorine-substituted polychlorinated biphenyls. Concentrations of target compounds varied with locations and sample matrices. In general, KDTW sediment samples contained slightly higher amounts of PCDD/DFs (average: 1100, range: 120-2400) than the LE sediments (average: 920, range: 580-1300) on a pg/g dry wt (dw) basis. Dioxin-like PCBs in KDTW were (average: 550, range: 70-2,000) higher than in LE (average: 320, range: 44-1000) on a ng/g dw basis. In contrast, mussel tissues had greater concentrations of PCDD/DFs in LE (average: 6500, range: 2200-13,000) than in KDTW (average: 3500, range: 2500-4800). Dioxin-like PCBs were slightly higher in KDTW (average: 76, range: 18-100) than in LE (average: 49, range: 24-96) on a ng/g fat wt basis. Biota sediment accumulation factors (BSAFs) were calculated using tissue concentrations and sediment concentrations based on dry weight. PCDD/DFs BSAF was in the range of 0.21-25 in LE and 0.093-13 in KDTW. 1,2,3,7,8,9-HxCDF in LE and 2,3,7,8-TCDF in KDTW had a greater BSAF, while BSAF for dioxin-like PCBs ranged from 0.84 to 13 in LE and from 2.3 to 12 in KDTW in which PCB-169 had the greatest BSAF in LE and PCB-167 in KDTW. Toxic equivalency (TEQ) was greatest in mussel from LE (mean: 193 pgTEQ/g fat wt) followed by mussel from KDTW (32 pgTEQ/g fat wt), sediment in KDTW (13 pgTEQ/g dry wt), and sediment in LE (7.6 pgTEQ/g dry wt). In general, PCDD/DF had a greater contribution to toxicity in mussels, while dioxin-like PCBs had a greater contribution to toxicity in sediment at both locations.