Fatigue of airport pavements is an important consideration in the analysis of high-traffic pavements. The current pavement condition index (PCI) method of pavement evaluation does not adequately evaluate fatigue cracking of airport pavements and should be considered for modification. Recent field inspections by the authors of Atlanta Hartsfield International Airport, Dallas-Fort Worth International Airport, and Albuquerque International Sunport have shown the fatigue cracking in thick concrete pavements to be prevalent. However, it is not normally recorded in a normal PCI inspection because the crack widths are less than 3 mm (1/8 in.). A properly designed, constructed, and maintained pavement should theoretically fail only in fatigue because all other distresses caused by construction deficiencies, material deficiencies, environmental distresses, and maintenance deficiencies would be avoided. Therefore, it is important for the management of airport pavements that receive high levels of traffic to consider fatigue-cracking distress. In practice, it is not possible to sample 100% of pavements to fully evaluate all hairline cracking. However, a geographical distribution of pavement control sections can be established and monitored for changes over time. The PCI should be revised or a new distress identification method should be developed to account for fatigue cracking.