The compilers of biographies described him as being of medium-hight, not tall not short, of bright face, white color impregnated with redness, with thick beard, of wide shoulders, and the best smiley person.
He was known for generosity and spending in the way of Allah, and we previously mentioned some of that.
As for his worship, he frequently fasted and stayed up at night for worship. Ibn `Umar commented on the saying of Allah: "Is one who is obedient to Allâh, prostrating himself or standing (in prayer) during the hours of the night, fearing the Hereafter and hoping for the Mercy of his Lord (like one who disbelieves)?" [Surat Az-Zumar: 9]. saying: That is the description of `Uthman.
Of his great sayings which indicate his devoutness and piety that he used to say: I have not committed adultery nor theft neither in Jahiliyyah (pre-Islamic time of ignorance) nor in Islam.
He (may Allah be pleased with him) was killed in 35 AH when the people besieged his house in the famous sedition when he was eighty years old.
He sacrificed himself and was martyred unjustly where he could have asked the help of the Companions of the Prophet to defend him, but he did not desire that a drop of blood is being spelled because of him.
The Prophet (peace be upon him) informed him that he shall be killed unjustly and that was a Prophetic sign. At-Tirmidhy reported in his Sunan from the Hadith of Ibn `Umar who said: The Prophet (peace be upon him) mentioned a sedition and said: "(pointing at `Uthman) this will be killed therein unjustly."