Liquid viscosity is an important thermophysical property in process design. While liquid viscosity has been studied for over a century, much has been left unexplored. The behavior of liquid viscosity between the melting point and normal boiling point are well established, but yet there is a lack of experimental data – with only 52% of the compounds in the 801 DIPPR database having experimental liquid viscosity data – and inadequate prediction methods. This project was able to measure liquid viscosity for 30 organic compounds to help fill in the gap in the 801 DIPPR database. The measured results also helped reiterate the need to examine family trends when looking at thermophysical properties. Prediction method shortcomings are briefly discussed when evaluating measured liquid viscosity data. A QSPR model developed by Gharagheizi is tested using liquid viscosity data from the 801 DIPPR database and found to be nonreplicable. A new QSPR model for predicting liquid viscosity at 298.15 K based on chemical family is developed and proven to be a promising starting point for future work.