Vacuum-tumbling marination is often used to improve the yield and quality of whole or portioned broiler breast fillets. The relationship between the marination performance of whole Pectoralis major muscles and breast fillet sub-samples is not well understood. The objective was to determine the effects of sub-sampling and freezing-thawing on the marination performance and cook loss of broiler breast meat. Paired right and left breast fillets were marinated as whole fillets or sub-samples (cranial and mid-caudal portions). Samples were marinated at 48 h postmortem (fresh) or stored at -20°C and then thawed prior to marination (frozen-thawed). Samples were vacuum-tumbled in 20% wt/wt brine (5% NaCl, 3% STP) and weighed pre-marination, during marination (15, 30, and 45 min), and 24 h post-marination. Samples were then cooked to 75°C for determination of cook loss. Marinade uptake was greater in caudal sub-samples than intact fillets and cranial sub-samples after 15 min of marination (P < 0.0001). After 30 min, marinade uptake was greater in caudal sub-samples and intact fillets than cranial sub-samples (P < 0.05). After 45 min, marinade uptake for fresh samples was greatest in intact fillets and lowest in cranial sub-samples. For frozen-thawed samples, marinade uptake at 45 min was greater in caudal sub-samples and intact fillets than cranial sub-samples (P < 0.0001). Marinade uptake in sub-samples at 30 min was greater in frozen-thawed versus fresh fillets (P < 0.05). Differences in marinade retention were not observed. Cook loss was similar between fresh and frozen-thawed samples but was greater in sub-samples compared to intact fillets (P < 0.0001). Correlations between marinade uptake in intact fillets and cranial sub-samples were greater in fresh (r = 0.64 to 0.78) than frozen-thawed samples (r = 0.39 to 0.59). Correlations between marinade uptake in intact fillets and caudal sub-samples were greater in frozen-thawed (r = 0.79 to 0.82) than fresh samples (r = 0.46 to 0.63). Data suggest that the relationships between marination performance of whole breast fillets and fillet sub-samples are dependent upon prior sample handling and intra-fillet sampling location.