The axial fatigue behavior of both notched and unnotched graphite/ epoxy composites has been studied as part of a continuing research investigation. In unnotched studies, conducted on a [0/±30]_3s AS/3501 laminate, S-N (Δσ-log N_f) curves were determined for various stress ratios R using simply supported test specimens. Specimens were fatigue tested up to 5 × 10⁶ cycles. Apparent fatigue limits (defined as stress amplitude at 5 × 10⁶ cycles) in tension-tension (T-T) and compression-compression (C-C) cycling occurred at about 60 percent of the respective static strengths. The overall results were expressed in the form of a constant life diagram (that is, a Goodman diagram) showing the relationship between mean stress and stress amplitude. The diagram shows a linear relationship and illustrates a skew-symmetry in fatigue life caused by the relatively low compressive strength of the unrestrained test specimens used. In effect, a maximum in stress amplitude occurs at a positive value of the mean stress. Results of this study are of significance in situations where structural members are buckling or crippling critical in design.