This essay investigates the influence of Ancient Persian Illumination philosophy on the philosophy of Suhrawardi. Shaikh Shahab al-Din Suhrawardi, known as Shaikh al-Ishraq (Master of Illumination) was a 12th century philosopher and mystic. He is considered to be the founder of Illumination philosophy and also the reviver of ancient Persian philosophy of light and Illumination. To put it differently, the ancient Illumination philosophy is reflected in his works. Shaikh al-Ishraq was able to write something which no one before him had ventured to write. Given his philosophical achievements, he considered himself a torchlight in the history of philosophy. Having studied the influence of ancient Persian philosophy, it can be concluded that all such influence can be summarized in terms of the principle of light which was borrowed from ancient philosophy. According to this idea, Suhrawardi called his philosophy the philosophy of Ishraq, meaning light and illumination. His basic notions are explained in relation to this principle of light. In his philosophical system, Suhrawardi divides the world into light and darkness and also uses many notions from ancient philosophy, including, shahriwar (one of the gods in Zoroastrianism, heavenly kingdom) and huraxš (burning light, the sun). This study uses the existing literature on Suhrawardi and an analytical-descriptive method to discuss the topic.