Background: Length–weight relationships and condition factors of giant tiger shrimp Penaeus monodon (Fabricius, 1798) from four breeding families (family S: South China seas family, family A: African family, family SA: ♂ South China seas family × ♀ Africa family, family AS: ♂ Africa family × ♀ South China seas family) were evaluated in this study. Findings and conclusion: Length–weight relationships can be expressed as W = 0.0239BL 2.789 (R 2 = 0.8977) in family S, W = 0.0206BL 2.9107 (R 2 = 0.9107) in family A, W = 0.0211BL 2.831 (R 2 = 0.8869) in family SA, and W = 0.0249BL 2.781 (R 2 = 0.9159) in family AS. The growth of P. monodon from four breeding families follows a negative allometric trend. Fulton’s body condition factor (K) was not significantly different in males, while in females, the highest K (3.07) was observed in family AS, and the lowest K was found in family A (1.88). Results from the present study indicate that the cross group family AS (♂ Africa family × ♀ South China seas family) has obvious heterosis in females. This may suggest that the direction of further breeding of P. monodon, should be conducted by using Africa family as male parent, and South China seas family as female parent. Results from the present study will provide valuable information on selective breeding in P. monodon. Methodology used in the present study can also be applied in other similar species.