The physical nature to the concept of Mizaj-e-Advia (temperament of drugs) warrants its critical evaluation, which is possible only when the physical correlate of Mizaj is made comprehensive and empirical. This work is a preliminary attempt towards this goal. In the context of the importance of organoleptic characters and physical properties of drugs for Mizaj assessment, Ibn Rushd in Kitab-ul Kulliyat emphasizes on the need for further evaluation of the physical correlates of Mizaj. From the basic rules of stating the nature of drugs as hot, cold, moist or dry from its organoleptic characters and physical properties as stated in the classical texts, an inventory was developed consisting of a battery of tests Mufrad drugs were subjected to. The score obtained through inventory is correlated to the classical description of Mizaj and Darjae Mizaj for its reliability. From the definition of the Darjate Mizaj and its correlation with acute toxicity (LD50) appears a suitable criterion for its validity for classical Mizaj description as well as inventory scores. The inventory showed fair accuracy when applied to a group of drugs. In view of these attributes of reliability and validity, this instrument may be useful to determine the temperament of single drugs.