Del Rosario's professional military training includes: Scout Ranger Course and Basic Airborne Course where he ranked third out of 103 in 1980; Field Artillery Officer Basic Course at Combat Arms School, TC, PA in 1989 where he topped his class; Field Artillery Officer Advance Course at Fort Sill, Oklahoma, USA in 1991; Pre-Command Course for Battalion Commanders at the CGSS, TRADOC, PA in 1995; Command and General Staff Course in CGSS, TRADOC, PA in 1999; and Counter Terrorism Course at Naval Postgraduate School, California, USA in 2003.