Short answer
Yes. Urinating breaks wudu by agreement of all Muslim scholars, even a single drop. Anything that leaves the front or back passage breaks wudu, and the Hanafi school adds flowing blood, a mouthful of vomit, sleep lying down, fainting and loud laughter in prayer.
Urine, stool, wind, madhy (pre-seminal fluid) and any other discharge from the two passages break wudu. Hanafi texts add: blood or pus that flows, a mouthful of vomit, sleep lying down or reclining, losing consciousness, and loud laughter during a prayer with ruku and sajdah.
The four schools agree on this.
Explanation
The Quran names coming "from the place of relieving himself" as a reason to purify before prayer, and the four schools agree that urine and stool break wudu (ablution). Even a drop of urine that leaks after you have made wudu breaks it.
The full Hanafi list of things that break wudu:
- anything leaving the front or back passage: urine, stool, wind from the back, madhy, wadi, discharge
- blood, pus or fluid that flows from a wound (details)
- vomit that fills the mouth (details)
- sleep lying down or leaning heavily (details)
- fainting, intoxication or losing your mind
- loud laughter in salah (details)
Things that do not break wudu in the Hanafi school: touching your private parts, touching the opposite sex, eating camel meat, sweating, burping, cutting your nails or hair, and seeing your own or someone else's awrah. Some of these do break wudu in other schools, and each has its own answer in this section.
After urinating, men should wait for the last drops before washing (istibra), so that drops do not leak out after wudu. If you have a condition where urine keeps dripping, the rules of a ma'dhur (excused person) apply.
The evidence
Quran, Surah Al-Maaida 5:6
يَٰٓأَيُّهَا ٱلَّذِينَ ءَامَنُوٓا۟ إِذَا قُمْتُمْ إِلَى ٱلصَّلَوٰةِ فَٱغْسِلُوا۟ وُجُوهَكُمْ وَأَيْدِيَكُمْ إِلَى ٱلْمَرَافِقِ وَٱمْسَحُوا۟ بِرُءُوسِكُمْ وَأَرْجُلَكُمْ إِلَى ٱلْكَعْبَيْنِ ۚ وَإِن كُنتُمْ جُنُبًۭا فَٱطَّهَّرُوا۟ ۚ وَإِن كُنتُم مَّرْضَىٰٓ أَوْ عَلَىٰ سَفَرٍ أَوْ جَآءَ أَحَدٌۭ مِّنكُم مِّنَ ٱلْغَآئِطِ أَوْ لَٰمَسْتُمُ ٱلنِّسَآءَ فَلَمْ تَجِدُوا۟ مَآءًۭ فَتَيَمَّمُوا۟ صَعِيدًۭا طَيِّبًۭا فَٱمْسَحُوا۟ بِوُجُوهِكُمْ وَأَيْدِيكُم مِّنْهُ ۚ مَا يُرِيدُ ٱللَّهُ لِيَجْعَلَ عَلَيْكُم مِّنْ حَرَجٍۢ وَلَٰكِن يُرِيدُ لِيُطَهِّرَكُمْ وَلِيُتِمَّ نِعْمَتَهُۥ عَلَيْكُمْ لَعَلَّكُمْ تَشْكُرُونَ ﴿٦﴾
O you who have believed, when you rise to [perform] prayer, wash your faces and your forearms to the elbows and wipe over your heads and wash your feet to the ankles. And if you are in a state of janabah, then purify yourselves. But if you are ill or on a journey or one of you comes from the place of relieving himself or you have contacted women and do not find water, then seek clean earth and wipe over your faces and hands with it. Allah does not intend to make difficulty for you, but He intends to purify you and complete His favor upon you that you may be grateful.
Names relieving oneself as an act that requires purification before prayer.
Sahih Muslim 224
Sahih... لا تقبل صلاة بغير طهور ...
"No prayer is accepted without purification."
Shows that once wudu is broken, prayer needs a fresh wudu.
Where the ruling is recorded
- Nur al-Idah with Maraqi al-Falah, Chapter on what breaks wudu. Lists the breakers of wudu in the Hanafi school.
- al-Hidaya, Kitab al-Taharat, chapter on what breaks wudu. Anything that leaves the two passages breaks wudu.
This answer is pending review by the scholars on our team. Quran translation by Sahih International. Hadith Arabic from the standard editions of the six books and the Muwatta, with gradings as recorded there; the English is our own rendering. Spotted a mistake? Tell us.