To obtain the best thawing method for frozen tilapia fillets, this paper studied the effects of four thaw thawing methods, namely, chiller thawing in 4 °C refrigerator (CT), air thawing in ambient temperature (AT), vacuum-steam thawing (VT) and ultrasonic thawing (UT) on tilapia quality, by measuring the thawing time, thawing loss, 2-thiobarbituric acid (TBA), K value, and pH value, and observing the transverse section of thawed fillets using scanning electron microscope (SEM). Results indicated that, compared with CT and AT, the thawing time was significantly shorter (P<0.05) by VT and UT, and the thawing loss, TBA, K value and pH of thawed fillets varied slightly (P<0.05). SEM showed that thawing had an impact on the microstructure of muscles; the impact was minimal with VT method, ensuring the thawed tilapia similar to fresh fish to the largest extent; the fillet microstructure was rather severely damaged with UT, but was only slightly damaged with CT and AT. The study showed that VT method could shorten the thawing time and better maintain the physiochemical quality and microstructure of tilapia meat, and compared with AT method, thawing time decreased by 97.7%, thawing loss rate decreased by 87.5%, TBA value decreased by 92.3%, K value decreased by 61.7% and the microstructure was relatively intact. Therefore, VT is a more appropriate way to defrost tilapia fillets.