Rudolf Diesel married Martha Flasche. Their marriage was a significant stabilizing force in his life, providing him with a supportive home environment as he pursued his career and inventions.

The birth of Rudolf Diesel Jr. marked the beginning of Diesel's family life. He was reportedly a loving and devoted father.

The birth of Eugen Diesel further expanded the family. Eugen later became a biographer of his father.

The birth of Hedi Diesel completed the Diesel family. Despite his professional demands, he seemed to have maintained a strong relationship with his children.

Despite his demanding work schedule and frequent travel, Diesel maintained a close relationship with his family. He relied on their support and encouragement throughout his career, and his family played a vital role in his personal life.