Neutron exposure of the reactor pressure vessel is one of the factors that must be quantified when assessing safe vessel lifetime. As a result, the procedures for determining a neutron exposure level for the entire vessel or a critical location should have the same level of accuracy as other factors such as fracture potential based on known or projected mechanical properties. This paper considers the factors affecting neutron dosimetry and associated uncertainties that must be assessed prior to making realistic projections of the vessel condition. In addition, an attempt to describe in simple terms some complex, but important, areas of reactor vessel neutron dosimetry analyses will be made. Assessment of these issues will enhance the mutual understanding between nuclear physicists and chemists analyzing vessel dosimetry and the materials specialist evaluating the mechanical property changes.