Neptunus was the Hoofdklasse powerhouse of the early 21st Century. They won a record seven consecutive titles from 1999 through 2005 before several stars departed prior to the 2006 season, including 2005 MVP Dirk van 't Klooster and 2005 Pitcher of the Year Rob Cordemans. The absence didn't turn them much as they rebounded to be the league's top power again in the 2010s. Neptunus is located in Rotterdam and play their home games in Neptunus Familiestadion.
Previously known as Levi's Neptunus Rotterdam, Kok Juwelier Neptunus Rotterdam, KOK Neptunus Rotterdam, Tropicana Neptunus, and for many years DOOR Neptunus before being sponsored by the government of Curaçao, the club also won Hoofdklasse titles in 1981, 1991, 1993 and 1995. They also won the European Cup five consecutive seasons from 2000 through 2004 as well as in 1994, 1996, 2015, 2017 and 2018.
When Neptunus won the 2009 Holland Series, they tied Haarlem Nicols for the most titles (12) in league history. They became the first 13-time titlist when they won the 2010 Holland Series. After two years without a title, they won the 2013 Holland Series. They were the first Hoofdklasse team to 1,000 wins (on April 27, 2014), doing so after only 1,387 games; at least four other teams had more games played but Kinheim was second in wins at a distant 816 at that point. They also won five straight Dutch championships from 2014 through 2018.
|1981||29-7||Wim Onderstal||Champions||4th place|
|1983||19-17||Tim Schmidt||3rd place|
|1984||15-21||Harry van der Berg/Frans van Aalen|
|1991||27-8-1||Charles Urbanus Jr.||Champions||Runner-up|
|1993||24-17-1||Charles Urbanus Jr.||Champions||Champions|
|1994||25-15-2||Charles Urbanus Jr.||Runner-up||Champions|
|1996||25-10||Jan Collins||Semi final||Champions|
|1997||31-10||Bill Froberg||Semi final||Runner-up|
|2006||29-11||**||Semi final||5th place|
|2007||32-7||Eric de Bruin||Semi final||Champions|
|2008||31-11||Eric de Bruin||Semi final||5th place|
|2010||39-3||Steve Janssen||Champions||6th place|
|2011||31-11||Jan Collins||Semi final||5th place|
|2012||33-9||Jan Collins||Runner-up||5th place|
|2013||34-8||Evert-Jan 't Hoen||Champions|
|2014||34-7||Evert-Jan 't Hoen||Champions||3rd place|
|2015||33-9||Evert-Jan 't Hoen||Champions||Champions|
|2016||34-7||Evert-Jan 't Hoen||Champions||4th place|
|2019||36-6||Ronald Jaarsma||Runner-up||3rd place|
Note: The years 2002-2006 Neptunus went with 3 co-managers