In 1993, the Jascheks retired from Strasbourg Observatory. Due to poor health, they moved to Salamanca (Spain) to live with their daughter's family, and continued their scientific activities from their new location. The couple has been described as "inseparable in their life and in their work". Mercedes Jaschek died on November 21, 1995, and he was deeply impacted by the loss.
Jaschek continued making public presentations, and in 1998 he published a book on ethno-astronomy. He was remembered as someone who loved his family, astronomy and its impact on culture, teaching and history books, and was regarded as kind, optimistic, upright, and helpful. 
Carlos Jaschek died April 12, 1999, in Salamanca, Spain.