What is the minimum number of rak'ahs for the Qiyam prayer?

The preferred number of rak'ahs for Qiyam al-Layl (night prayer), whether in Ramadan or otherwise, is eleven rak'ahs, in imitation of the Prophet's actions (peace be upon him), as stated by Aisha (may Allah be pleased with her). It is permissible to exceed this number, as the night prayer is performed two rak'ahs at a time. If the worshiper fears the approach of dawn, he should pray one rak'ah of witr. As for the minimum number of rak'ahs for Qiyam al-Layl, it is the one rak'ah of witr, and the more a Muslim prays, the better it is for him.