In 1967, Keith began his love affair to Anita Pallenberg. She is an Italian born actress and model. They were in love relationship for twelve years. They had three children together. They never got married. Their third son died 10 weeks after his birth due to sudden infant syndrome. They separated in 1979.
In 1979, soon after his separation to Anita, he met Patti Hansen. She is an American actress and model. They married on 18 December, 1983 and that day was his 40th birthday. They got married at the Finisterra Hotel in Cabo San Lucas, Mexico. They have two daughters together. They are still together and happy being each other loving spouse. He earns massive amount of salary and his net worth is 340 million dollars.