Poertzel was German born, the third child of William G. Poertzel and his wife Emilie J. Candida. In elementary school he had private lessons with Kantor Secures and pastor Henkel. He was an apprentice at local porcelain factory where AW Fr. Kister took him on as an apprentice where he was trained as a porcelain designer like his father. In 1893 Otto Poertzel spent three years studying at the Technical Academy of porcelain in Sonneberg (Sonneberg Industrial School) at Reinhard Möller. By 1900 Poertzel worked as a freelance sculptor in Coburg. He received orders for stone and bronze sculptures by state and municipal authorities, creating, for example, in 1907 the bust of Alexandrinenbrunnens. In 1908 he owned his own studio in Munich and on June 23, 1909 he married Henny Breyding.   Otto Poertzel participated in numerous international art exhibitions with factory models, such as the St. Louis World’s Fair (1904) and at the Brussels International Art Exhibition (1910). In the 1920s and 1930s Poertzel received numerous commissions for portrait busts of various family members of the family of Saxe-Coburg and Gotha. From 1931 to 1938 he worked for the Max Roesler fine earthenware factory in Rodach. Poertzel became one of the most prominent sculptors in Germany and was for many years under the special protection of the Duke of Saxe-Coburg- Gotha who gave many commission orders. Many of his earlier works were to be found in the salons of German Royal Courts and a few of the most beautiful were purchased by the late King of Bulgaria.