Lieutenant Nguyen is the Potemkin's chief transporter operator. He is known to have played rugby for the New Zealand Blackshirts in his youth. He is also an expert water polo player and sometimes plays with other crewmembers in the ship's swimming pool. Additionally, Nguyen has demonstrated a moderate ability to play the Vulcan harp. He is known for his joking personality and banters with anyone who enters his transporter room.

Nguyen is referred to as "Chief", being the transporter chief, but he did start off as a non-commissioned officer. He eventually obtained a commission and holds his current rank of Lieutenant.

During "Doctor Nguyen/One Night Stand" Nguyen tried to compensate for an odd energy signal during transport, and the three women arrived on board pregnant. He later had to deliver the three children, explaining that his mother was midwife.

In "From Nguyen with Love (or "The Luckiest Man in Starfleet")" we saw an alternate timeline where Nguyen was able to repeat the same 30 years of his life twice. Using his foreknowledge, he managed to become captain of the Potemkin and started a romantic relationship with Arkin. However, this version of Nguyen eventually realized he had done more harm than good and he and the crew eventually corrected the timeline.

Nguyen was later revealed to be a member of Section 31 after he went against Elric Latiner in a bit to stop the latter's plan to destroy the wormhole. He revealed that his water polo trips were excuses to check in with his handlers. After being exposed he quite the organization - although he later admitted to Prax that he actually learned to love water polo during this time and still played.