Stanley found Livingstone on 10 November 1871 in Ujiji, near Lake Tanganyika in present-day Tanzania. He may have greeted him with the now-famous line, "Doctor Livingstone, I presume?" It may also have been a fabrication, as Stanley tore out of his diary the pages relating to the encounter. Neither man mentioned it in any of the letters they wrote at this time. Livingstone's account of the encounter does not mention these words. The phrase is first quoted in a summary of Stanley's letters published by The New York Times on 2 July 1872. Stanley biographer Tim Jeal argued that the explorer invented it afterwards to help raise his standing because of "insecurity about his background".

Preserving a calmness of exterior before the Arabs which was hard to simulate as he reached the group, Mr. Stanley said: – "Doctor Livingstone, I presume?" A smile lit up the features of the pale white man as he answered: "Yes, and I feel thankful that I am here to welcome you."

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