During his terms in office, Letnick served over four years as British Columbia's minister of Agriculture, the longest period in this portfolio of any BC Liberal.

As chair Letnick lead the hospital board through a strategic planning process, the creation of a new service agreement with the Regional Health Authority, and the hiring of a new CEO.

Letnick and his family moved to Kelowna, British Columbia in 1999 taking a faculty position at Okanagan University College teaching business administration.

[8] In the spring of 2005, with Member of Parliament Werner Schmidt announcing his retirement, Letnick sought the Conservative Party nomination in the Kelowna—Lake Country riding.

[12] Letnick was appointed to a two-person task force, with fellow councilor Michele Rule, to investigate and provide City Council with recommendations on affordable housing.

Based on the recommendations Kelowna council immediately decided to reserve 20% of a city-owned old school site for affordable housing development.

In 2013 Letnick won his riding for a second term with 57% of the vote and was appointed parliamentary secretary to premier Clark responsible for Intergovernmental Affairs.

In Fall 2009 Letnick was appointed by Randy Hawes, fellow BC Liberal MLA and the Minister of State for Mining, to lead a committee investigating a management strategy for aggregate extraction and processing in the Central Okanagan area.

Letnick voted against the bill as "a matter of conscience" saying that he supported the current methods used and that the act may dis-locate persons into unfamiliar parts of town without a means to return.

[29] The unpopularity of the HST within his riding led to Letnick being included in a list of 24 MLAs, in June 2010, who the FightHST group would explore for potential recall.

[34] In May 2011, Letnick introduced a private member bill called the Emergency Intervention Disclosure Act (M-210) into the Legislative Assembly.

Letnick cited encouragement from fire fighters and paramedics, as well as a Clark campaign pledge to debate more private member bills, as reasons for bringing the proposed legislation forward.

[35] Currently emergency workers and victims of crime who suspect they have been exposed to serious illness cannot determine their exposure until many months later, often past the window of preventative treatments.

Because of this doubt, suspected exposed people usually ingest a concoction of prophylactic drugs, and they, with their families, carry the mental burden of uncertainty.