Prostate-specific membrane antigen (PSMA) - based radiopharmaceuticals are promising for the evaluation of PSMA-positive non-prostate cancers. In this case study, 18F-BF3-Cy3-ACUPA and 68Ga-PSMA positron emission tomography/magnetic resonance imaging (PET/MRI) were compared in a patient with metastatic colon cancer. Both 18F-BF3-Cy3-ACUPA and 68Ga-PSMA PET/MRI showed biopsy-proven metastatic left external iliac adenopathy, highlighting the feasibility of PSMA uptake in PET/MRI of metastatic nodal disease from colon cancer. Along with imaging evaluation, PSMA-based radiopharmaceuticals may also be used as a surrogate imaging tracer for potential theranostic applications using alpha or beta emitters in the context of PSMA-directed radiopharmaceutical therapy in advanced and progressive colorectal cancer.