This work presents a study on feasibility to predict saturates plus mono-nuclear aromatic hydrocarbons content in vacuum gas oils from readily available physical properties and the empirical methods: n-d-M, API, Total, Conoco Phillips (COP), and that of Goosens. As a result of a wide literature search 44 vacuum gas oils (VGO) having saturate plus mono-nuclear aromatic hydrocarbons in the range 13.7-97.0% and specific gravity (SG) in the range 0.8648-1.0903 were selected. Based on the physical properties SG and T-50 boiling point of the 44 VGOs and the aromatic carbon and hydrogen content predicted by the Conoco-Phillips method a new correlation that predicts VGO saturate plus mono-nuclear aromatic hydrocarbons content with a reasonable accuracy was developed. This correlation based on a wide variation in properties of VGO can be used for a daily optimization of operation of FCC and hydrocracking units. (C) 2014 Elsevier Ltd. All rights reserved.