Purpose: The DISFORM dissection classification was created using a Delphi methodology to address the lack of a peripheral arterial classification system. This classification has recently been validated against clinical outcomes and showed that the DISFORM IV grade was an independent predictor of patency. Currently there is no data on the reliability of this method, which is vital in allowing for greater usage in clinical practice. This study aims to assess the reliability of the DISFORM classification. Methodology: Digital subtraction angiography images of the femoropoliteal arterial segment post angioplasty were retrospectively selected from 100 cases sourced from two studies investigating the use of IVUS in femoropopliteal disease. All cases were de-identified and presented in a form that could be viewed as “runs” simulating viewing during the procedure. Each case was scored by two blinded, independent readers using the DISFORM dissection classification system. A subgroup of 25 randomly selected cases was reanalysed three months after initial reading. Inter-observer and intra-observer agreement was tested using the kappa statistic. Results: Based on the 100 cases studied, the inter-observer reliability demonstrated moderate agreement (κ=0.552, p<0.001) using the DISFORM classification system. From the subgroup of 25 cases, the intra-observer reliability also demonstrated moderate level of agreement for both readers (reader 1 – κ=0.496 and reader 2 - κ=0.504). Conclusion: This study demonstrates that the DISFORM classification system has moderate inter- observer and intra-observer reliability. This should be taken into consideration when reporting femoropopliteal dissections and used to guide intraoperative planning and need for further scaffolding.