Yes. The Prophet Muhammed s.a.s. was sinless.

Holy KORAN 33:33:

> "Ve karne fî buyûtikunne ve lâ teberrecne teberrucel câhiliyyetil ûlâ
> ve ekımnes salâte ve âtînez zekâte ve atı’nallâhe ve resûlehu,
> **innemâ yurîdullâhu li yuzhibe ankumur ricse ehlel beyti ve yutahhirakum tathîrâ(tathîran)**." (Arabic verse in Latin letters)

Meaning: **The Ahl-ul Bayt (household of the Prophet) is pure.**

Word by word: "O people of the House! Allah only wishes to keep away the sin from you and to cleanse you with a thorough cleansing."

What Allah wishes, is already done. For he has created everything perfect.

Addition: 

Someone wrote, that Allah has said in 47:19 that the prophet should pray for his "sins". But in that Ayat it says "ZEN" (zan), this means, "faults", but not sins. In the Ayat I wrote it (above), where Allah says he will keep them free of sins, there stands: "RICS". "Rics" is everything that the religion and Allah has forbidden.