The purpose of the present study was to evaluate the consistency and reliability of alveolar bone height measurement using digital scanning radiographic image analysis (DSRIA). A randomly selected (standardized paralleling technique) periapical radiographs of 20 molar teeth (10 maxillary molars and 10 mandibular molars) from 178 individuals with periodontitis were reporting or referred to the patient population of the dental clinics of the teaching hospital. Radiographic measurements were performed and read by two examiners, with a separation time of three weeks of different tooth groups and as established by double reading of 20 molar teeth in 10 individuals using the DSRIA. The calculating data of radiographic alveolar bone loss (RABL) measured and analyzed by the DSRIA for each molar group were compared based on the inter- and intra-examiners' data. The means and standard deviations were calculated to compare radiographs of the inter- and intra-examiners' groups. The reliability coefficients were computed to assess the consistency and reliability for each molar group. The results revealed that the intra- and inter-examiners' reliability coefficients ranged from 0.986 to 0.995 (p < 0.001, significantly different from 0). An excellent reproducibility was indicated in maxillary molar, mandibular molar and of both arches, respectively. It was concluded that the standard periapical radiograph using the DSRIA has the potential to be a valuable and reliable method in measuring linear alveolar bone defects caused by periodontitis.