He married the third daughter of his uncle Yoshisada OISHI and had five sons; Yoshitaka OISHI (the head of chief retainers of the Asano family of Ako Domain), Yoshishige OISHI (a chief retainer of the Asano family of Ako Domain), Tomotomo OKUMURA (a vassal of the Matsudaira family of Toyama Domain), Yoshihide OYAMA (a vassal of the Asano family of Ako Domain, adoptive father of Yoshimoro OYAMA) and Yoshitsugu OISHI (a vassal of the Matsudaira family of Takamatsu Domain).
伯父にあたる大石良定の三女を妻に迎え、息子に大石良欽（赤穂藩浅野家筆頭家老）、大石良重（赤穂藩浅野家家老）、奥村具知（富山藩松平家家臣）、小山良秀（赤穂藩浅野家家臣・小山良師の養父）、大石良次（高松松平家家臣）の五人を儲けた。