In October 1952, Soedarpo Sastrosatomo established NVPD Soedarpo Corporation, his first business line that works in trading, import and distribution.
On 1 March 1953, Soedarpo took over NV ISTA (Internationale Scheepvaart Transport Agenturen) and became the Managing Director. In November later that year, Soedarpo created Indonesia Stevedoring Ltd (INSTEL). In 1956, INSTEL acquired Stroohoeden Veem (which then became PT Sinar Harapan Veem Indonesia - SHVI), the biggest stevedoring and warehousing company in Surabaya at that time.
On 13 November 1964, through ISTA, INSTEL, Soedarpo started PT Perusahaan Pelayaran Samudera "Samudera Indonesia", which he held as President Director until the year 2000 and as President Commissioner until his passing in 22 October 2007.
Throughout his career, Soedarpo was active in various professional and social organizations, among others as the General Chairman of INSA (Indonesian National Shipowners' Association). Soedarpo was also known as one of the District Governors Rotary International in Indonesia, and founder as well as the Chairman of the Rotary Indonesian Foundation.
In 1985, Soedarpo received the "Orde Van Oranje-Nassau" award from the Kingdom of Holland for his services for the community. In 1995, he received "Bintang Mahaputra Pratama" from the President of Indonesia. In 28 September 2000, Soedarpo was honored to be in the "Asia Maritime Hall of Fame" as an award for his career in building Samudera Indonesia as one of the well respected players in the Asian maritime industry.