Lee's first wife, a Malaysian-born doctor named Wong Ming Yang, died at the age of 31 on 28 October 1982 of a heart attack,[61] three weeks after giving birth to Lee's first son, Li Yipeng, an albino. In 1985, when he was 33, Lee married Ho Ching, a fast-rising civil servant who subsequently became the executive director and chief executive officer of Temasek Holdings.
Lee has one daughter – Xiuqi – and three sons – Yipeng, Hongyi and Haoyi (including the daughter and son from Lee's first marriage). Ho Ching's eldest son, Li Hongyi, was the winner of the Lee Kuan Yew Award for Math & Science in 2006, the same year he was commissioned as an officer in the Singapore Armed Forces (SAF).
Lee was initially diagnosed with lymphoma which he underwent chemotherapy for[62] in the early 1990s[63] then subsequently also underwent a successful robot-assisted keyhole prostatectomy on 15 February 2015 after being diagnosed with prostate cancer.[64][65] [66]
Lee has expressed his interest in computer programming, and has written a Sudoku solver in C++ in his spare time