Quran Ki Chaar Buniyadi Istlahein (Urdu: قرآن کی چار بنیادی اصطلاحیں; English trans:Four Key Concepts of the Qur'an) is a 1944 Urdu Islamic book by Abul A'la Maududi. The book is considered to have fundamental importance in the religious thoughts of the author which present Islam as a comprehensive system of life.

Quran Ki Chaar Buniyadi Istlahein describes the four Arabic terms which are frequently mentioned in Quran as a key to understand the holy book; Elah, Rab, Ibadat, and Deen. The authors unfolds meanings of the terms in their full literal and Shariah context.^[1][2][3]

The book has been criticized for giving birth to so-called political Islam. In his 1963 Urdu book "Taebeer Ki Ghalti" (The Error of Interpretation), the Islamic scholar Wahiduddin Khan accused the author of presenting his own self-created meanings of the Arabic terms that are not found in writings of conventional academics and mainstream commentators.^[4] Another scholar Abul Hasan Ali Hasani Nadwi, in his 1978 Urdu book "Asar e Hazir Mein Deen Ki Tafheem o Tashreeh", also criticized the interpretations described in Maududi's Quran Ki Chaar Buniyadi Istlahein.^[5]

Quran Ki Chaar Buniyadi Istlahein is one of 20 books of Maududi that were banned in Saudi Arabia in 2015 by the Saudi Ministry of Education.^[6]