Short answer
It is disliked (makruh) in the Hanafi school, and the four schools discourage it. The Prophet ﷺ forbade urinating in the place where you bathe and warned that it causes waswasa. If you did, rinse the floor well and wash your feet and legs before you finish. Urinating in still water you will use is more strongly disliked.
Urinating in the place of bathing or wudu is makruh, especially where water does not drain away. Urinating into still water is makruh tahrimi, and into running water makruh tanzihi. Urine on the body must be washed off before the shower ends for the body to be pure.
The four schools agree on this.
Explanation
The Prophet ﷺ forbade a man from urinating in his bathing place, and said that most waswasa comes from it. Some hadith scholars graded this report weak and others accepted it. He also forbade urinating in still water and then bathing in it, in a report that is sahih. The scholars of the four schools agree that urinating where you wash is disliked.
Why it causes problems:
- Urine runs across the floor and splashes back onto your feet and legs.
- You then wonder whether your body and ghusl are clean, which is exactly the waswasa the hadith mentions.
- In a bath or a shower tray that drains slowly, you end up standing in impure water.
If it has happened:
- Rinse the floor with plenty of running water so the urine goes down the drain.
- Wash your feet and lower legs last, after the floor is clean.
- Your ghusl is still valid: urine on the skin is najasah to be washed off, not something that cancels the washing. If it happened after you washed, your wudu (ablution) is broken, so make wudu again before praying.
- Clean the area with water as part of istinja: see istinja.
A modern shower with a strong drain is lighter than a tub of standing water, but the sunnah is still to use the toilet first. Good habits here save you a lot of doubt later. If you struggle with doubts about cleanliness, see doubts about najis.
The evidence
Jami' at-Tirmidhi 21
Grading to be checked... نهى ان يبول الرجل في مستحمه وقال ان عامة الوسواس منه ...
"He forbade a man from urinating in his bathing place, and said: most waswasa comes from it."
The direct prohibition; some scholars graded it weak, so it supports rather than founds the ruling.
Sahih al-Bukhari 239
Sahih... لا يبولن احدكم في الماء الدائم ...
"None of you should urinate in still water."
A sahih prohibition that supports avoiding urine where you wash.
Where the ruling is recorded
- al-Durr al-Mukhtar with Radd al-Muhtar, Kitab al-Taharah, makruhat of relieving oneself. Urinating in water and in the place of bathing or wudu is disliked.
- al-Majmu' (Nawawi), Kitab al-Taharah, manners of relieving oneself. Urinating in the bathing place is disliked.
Checked by our team. For a more accurate answer to your own situation, consult a scholar. 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.