His great-grandmother Kahalemanuolono was the sister of Kamakahelei, making Piʻikoi a distant cousin of King Kaumualiʻi of Kauaʻi.

Returning to Kauaʻi after Kamehameha II's departure to Great Britain, Piʻikoi assisted the newly appointed Governor Kahalaiʻa Luanuʻu in suppressing Humehume's rebellion in 1824.

[3][4] Returning to Oʻahu, he served Kahalaiʻa until his death in 1826 and afterward became a servant of Kamehameha III.

During the Great Māhele, he was given the duty of separating the King's land from that of the chiefs'[4][1] He would later serve in the House of Nobles 1845–1859 and on the Privy Council 1852–1855.

[6][7] Before his death, he wrote an autobiography Sketch of J. Piikoi's Life which was published by the Pacific Commercial Advertiser on May 12, 1859.

Piʻikoi built the first two-story wooden house in Kewalo, which is now near the President William McKinley High School.