In 1990 he commenced studies at the Military Academy of Land Forces in Wroclaw. Promoted to the rank of Second Lieutenant in 1994, he initially served as a Platoon Leader and later as a Company Commander and Chief of Staff of a battalion in the 14th Mechanized Brigade in Elblag. After graduating from the National Defense University in Warsaw in 2002, he was appointed to the position of Specialist, Armed Forces Development Planning Department (J5), General Staff of the Polish Armed Forces.
In July 2004, he was deployed with the 3rd rotation of the Polish Military Contingent to Iraq where he led the Visitors and Observer Bureau, Multinational Division Centre-South. After this operational assignment, he was assigned the role of Mechanized Battalion Commander, 9th Armored Brigade in Braniewo in 2005. Two years later, in March 2007, he deployed with his battalion to the United Nations Disengagement Force in Syria where he served as the Commander of the Polish Military Contingent. After his return to Poland, he was appointed Chief of Staff of the 9th Armored Brigade in Braniewo.
In July 2008, he became Chief of the Operations Branch (G3) at the HQ of the 16th Mechanized Division. While in this position, he was deployed to Iraq in November 2008 where he occupied to position of Chief Training&Education Synchronization Cell of the NATO Training Mission. In August 2010, he began studies at the NATO Defense College, Rome, Italy. Between 2011 and 2014, he served as Chief of the Land Forces Employment and Analysis Division, Operational Planning Directorate (J3), General Staff. While in this position, he attended three courses at the NATO School in Oberammergau: NATO Crisis Management Course, NATO Crisis Response System Course for Experts, and NATO Senior Officer Policy Course.
In September 2014, he resumed studies with a postgraduate course in Defense Policy at the National Defense University, Warsaw. After successful graduation, he was appointed to the position of Senior Expert, Armed Forces Operational Planning and Training Directorate (J3/7), General Staff. In September 2016, he received a doctor’s degree in Social Science, specializing in Security Studies. In May 2016, he took command of the 15th Mechanized Brigade. On the 29th of November 2016, the President of the Republic of Poland appointed him to the rank of Brigadier General. In April 2017, he became the first Polish commander to integrate an eFP into the 15th Mechanized Brigade. The same year, he participated in the Generals, Flag Officers and Ambassadors Course at the NATO Defense College, Rome. In July 2018, he became Deputy Commander of the 12th Mechanized Division.
In September 2018, he assumed command of the 18th Mechanized Division. The experience he had gained working with the eFP helped him reorganize the 18th Mechanized Division according to new NATO standards, making this unit the most NATO-compatible division. On the 11th of November 2018, he was appointed to the rank of Major General by the President of the Republic of Poland.
In 2019, he completed the Senior Leaders’ Course at the Baltic Defense College in Tallinn, Estonia.
In June 2021, when commanding the 18th Mechanized Division, he prepared his staff for certification which took place according to CREVAL procedures. His division is now certified as combat-ready.
The same year, he graduated with honors from the postgraduate Master of Business Administration (MBA) / Cyber Security Management Program at the Institute for Cybernetics of the Polish Military Technological University, Warsaw.
In 2022, he completed the Senior Strategic Leadership Program at the Defense Academy of the UK, Shrivenham, England. On August 8th, 2022, he was appointed Deputy Commander for Interoperability, Security Assistance Group – Ukraine (SAG-U).
Lieutenant General Jaroslaw GROMADZINSKI assumed command of EUROCORPS on June 29, 2023.