From 2013 to 2015, the CORESTA Smokeless Tobacco Sub-Group (STS) conducted a series of collaborative studies for the determination of benzo[a]pyrene (B[a]P) in tobacco and smokeless tobacco products. The STS eventually settled upon a gas chromatography mass spectrometry (GC-MS) method using solid phase extraction for sample cleanup. A final collaborative study was conducted in the fall of 2015. The goal of this work was to calculate repeatability and reproducibility (r & R) and draft a CORESTA Recommended Method (CRM) for the determination of B[a]P in tobacco and smokeless tobacco products. The study results demonstrated that the method is suitable for the determination of B[a]P in tobacco, cigarette filler, and smokeless tobacco products and that the results were suitable for inclusion into a CRM.