The study focused on understanding the reproductive biology of Pinctada margaritifera, commonly known as the black-lipped pearl oyster, which holds significant economic importance due to its production of Tahitian cultured pearls. Research conducted in Mabahiss Bay, the Red Sea, Egypt throughout 2022 provided crucial insights into the reproductive cycle of P. margaritifera. The species exhibits protandric hermaphroditism, transitioning from male to female during its growth. Shell sizes inversely correlated with sex distribution, with a sex ratio of 1.05: 1.0: 0.1 for females, males, and undifferentiated individuals, respectively. The study identified a distinct spawning phase from June to October, peaking in July and August. Analyses of gonad index fluctuations in females and males provided additional understanding of reproductive dynamics. Among the methods tested to stimulate spawning, hormones, and gonad stripping yielded positive results. The research also delved into the timing and early development stages of eggs and larvae of P. margaritifera.