This report presents the number of high school graduates, the Averaged Freshman Graduation Rate (AFGR), and dropout data for grades 9 through 12 for public schools in school year 2005-06. The counts of graduates, dropouts, and enrollments by grade (which serve as the denominators for the graduation and dropout rates) are from the Common Core of Data (CCD) non-fiscal surveys of public elementary/secondary education. The data for this collection were reported to the National Center for Education Statistics (NCES) through the U. S. Department of Education's "EDFacts" data collection system by state education agencies (SEAs). These data represent high school graduates receiving regular diplomas for the 2005-06 school year and dropouts from the 2005-06 school year. The report includes counts of high school graduates for school year 2005-06 for 48 states, American Samoa, the Commonwealth of the Northern Marianas Islands, and Puerto Rico. High school graduation data were suppressed for the District of Columbia because in the data submitted the number of diplomas awarded exceeded the number of students in twelfth grade. Data for high school graduates were missing from CCD reports for Pennsylvania, South Carolina, the Bureau of Indian Education, the Department of Defense domestic and overseas dependents schools, Guam, and the U.S. Virgin Islands. This report includes 2005-06 school year dropout data for 49 states and 4 other jurisdictions. Dropout data were missing for charter schools in the District of Columbia, and the data therefore have been suppressed in this report. The extent of missing data resulted in some suppression of dropout counts from Vermont. South Carolina, the Bureau of Indian Education, the Department of Defense domestic and overseas dependents schools, and Guam did not report dropouts. Selected findings include: (1) Across the 48 reporting states, a total of 2,649,001 public school students received a high school diploma in 2005-06, resulting in an averaged freshman graduation rate (AFGR) of 73.4 percent, ranging from 55.8 percent to 87.5 percent in Wisconsin; (2) Comparisons of data from 2002-03 through 2005-06 show that the AFGR increased consistently over these 4 years for a total gain of 4 percentage points or more in Hawaii, Kentucky, New Mexico, New York and Tennessee; (3) There were more than 579,000 dropouts from high school (grades 9 through 12) among 48 reporting states in 2005-06, an overall event dropout rate of 4.0 percent, ranging from 1.6 to 8.9 percent in Alabama; (4) High school event dropout rates among the reporting states were highest for American Indian/Alaska Native students (7.4 percent) and lowest for Asian/Pacific Islander students; (5) Among the 48 states for which comparisons between 2002-03 and 2005-06 could be made, the event dropout rate increased for 27 states and decreased for the remaining 21; (6) Urbanicity was associated with differences in graduation and dropout rates across the four US regions; and (7) School district size was associated with differences in graduation and dropout rates. Methodology and Technical Notes are appended. (Contains 2 footnotes and 8 tables.)