Prayer: Is It Valid to Pray ‘Ishā’ Behind Someone Praying Maghrib?

Practical Laws of Islam as per the teachings of Imam Khamenei

Prayer: Is It Valid to Pray ‘Ishā’ Behind Someone Praying Maghrib?

English:

Question #573:

Is it correct to perform one’s ‘ishā’ prayer behind one who is performing the maghrib prayer?

Answer #573:

There is no objection to doing so.

-Imam Khamenei, Practical Laws of Islam, Importance and Conditions of Prayer