The merging of art production and technological innovation during the Renaissance in Europe led to some of the world's most renowned master works in bronze. Published technical studies of such bronzes are still relatively few in number. The objective of the present study was to conduct a comprehensive investigation of comparative examination and analysis on fifty-two bronze sculptures which were attributed to a wide variety of workshops and individual artists. The sculptures are housed in the permanent collection of the Kunsthistorisches Museum in Vienna, Austria, and were shown in the museum's 1987 exhibition, Renaissance Master Bronzes. Technical analysis included identifying and characterizing casting and fabricating techniques through visual surface examination; studying x-radiographs; and identifying clay core materials through thin-section petrography. The results of these studies were subsequently compared to technical treatises/accounts of bronze techniques by three Renaissance artist-scholars: Biringuccio (ca. 1540), Vasari (ca. 1550), and Cellini (ca. 1568). The present investigation shows a strong correlation between its technical results and those set forth by the above scholars from the Renaissance period. The findings of this research and comparison indicate that many methods and procedures in Renaissance bronze production were not standardized. Rather, there is shown to have been a wide range of technical variation. The broad variance is demonstrated through numerous processes, including: modes of separate cast-piece attachment, armature construction, chaplet insertion, selection of clay core and additive materials, and removal of clay core portions after casting. The variance is also evident in the quality and extent of surface tooling and/or chasing, and in the visual appearance of patinas. One result of this study is a better understanding of the nature of bronze sculpture technology during the Renaissance period.