The aim of the present study was to assess the cumulative radiographic periodontal attachment loss (CRPAL) and annually radiographic periodontal attachment loss (ARPAL) of different disease groups over 5 years or more. A total of 53 subjects, who had taken two sets of full-mouth standarized paralleling radiographs with separated periods of 5 years or more in teaching hospital during 1981-2001, were collected for the past 20 years. The radiographic periodontal attachment levels at mesial and distal surfaces of teeth were assessed by measuring the distance between cement-enamel junction and the bone crest using an electronic digital caliper (EDC) under a 10X magnified radiographs. The results revealed that mean CRPAL was highest in the generalized aggressive periodontitis (GAgP) group (-5.523.27 mm), then the chronic periodontitis (CP) group (-4.823.47 mm), and the localized aggressive periodontitis (LAgP) group (-4.473.47 mm) followed, and lowest in the periodontal healthy (PH) group (-1.050.59 mm). The mean ARPAL was highest in the LAgP group (-0.260.25 mm/yr.), then the GAgP group (-0.200.13 mm/yr.), and the CP group (-0.120.09 mm/yr.) followed, and lowest in the periodontal healthy group (0.070.06 mm/yr.). Conclusions showed that mean CRPAL was highest in the generalized aggressive periodontitis group, then the CP group, and the LAgP group followed, and lowest in the periodontal healthy group. In addition, there existed a strong statistical significance (p<0.0001) in both CRPAL and ARPAL (mm) among individuals affected GAgP, LAgP, CP, and PH groups among mild, moderate, and severe periodontitis using paired t-test.