Yes, Zulfikar Ali Bhutto and his family were Shia Muslims.
The Bhutto family, originally from Sindh, were aristocratic and wealthy landlords, considered part of the wadero or landed gentry of the region. His father, Shah Nawaz Bhutto, was a prominent politician. The family's religious affiliation was Shia Islam. This fact is generally accepted and documented within historical and political accounts related to the Bhutto family and Pakistani politics.
