Purpose:To demonstrate the feasibility of a MRI alone workflow to support treatment planning and image guidance for abdominal radiotherapy.Methods:Abdominal MR images (in‐phase/out‐phase/fat/water) were acquired for a patient with breath‐hold using a Dixon pulse sequence. Air masks were created on in‐phase images using intensity thresholding and morphological processing methods in order to separate air from bone. Pseudo‐CT and DRRs were generated using a published method. To investigate the effect of heterogeneity corrections on dose calculations using pseudo‐CT, three different plans (3‐field 3D, 5‐field IMRT and 2‐arc VMAT) were performed to mimic pancreatic treatments (1.8Gy/fraction over 28 fractions).Results:The DRRs created from pseudo‐CT were of comparable quality as those created from CT. Comparing dose calculations with and without heterogeneity corrections between the 3 different plans, the biggest dosimetric differences were seen in the VMAT plan where modulation must occur across air‐tissue interfaces such as those of the stomach and bowel. The DVHs for the VMAT plan showed ∼84cc difference at V50Gy in the small bowel. In terms of pseudo‐CT quality, some small volumes of air in the bowel and stomach were misclassified as bone. The VMAT plan was re‐optimized on pseudo‐CT with 0 HU in the misclassified areas. The V50Gy in the small bowel differed by ∼90cc between the new VMAT plan with and without heterogeneity corrections.Conclusion:We found that the use of MRI alone is feasible for abdominal treatment planning and image guidance. A difference between calculations with and without heterogeneity corrections was found that is most pronounced for VMAT where the traversal of air‐tissue interfaces is unavoidable. Future work will be performed to minimize misclassification between bone and air.