[11][12][13] During Lamothe's tenure as Prime Minister, foreign direct investment increased to the highest level since the fall of the Duvalier dictatorship in the mid-1980s.

[14] Under his leadership, the government pursued reforms that made Haiti a safer and more business-friendly country[15] with the implementation of a 15-year tax break[16] to companies investing in the island nation.

He also pushed for an increase of the police force by 30 percent,[17] spearheaded the free education program,[18] and promoted good governance by tackling corruption.

[24] Lamothe was subjected to three audits conducted by the Cour Supérieure des Comptes et du Contentieux Administratif,[25] the authority responsible for controlling public expenditures in Haiti.

[26] In July 2015, Lamothe created LSL World Initiative, a private enterprise providing solutions to governments in implementing their own funding mechanisms to help them deliver sustainable development programs in line with their needs and priorities.

After Hurricane Matthew struck Haiti, the Dr. Louis G. Lamothe Foundation has been working in Anse du Clerc to help the town recover from the damages.

[29] On 20 November 2022, Lamothe was sanctioned by the Canadian government for his involvement in human rights violations and supporting criminal gangs.

[31] A press release by the office of Canadian Prime Minister Justin Trudeau mentioned that Lamothe is "suspected of protecting and enabling the illegal activities of armed criminal gangs.

Lamothe has adamantly pushed back on the allegation, accusing the United States of falling for the “false narrative” of the Haitian political discourse that for years has sought to assassinate his character.

[37] Since taking office and after his resignation Lamothe's tenure as Prime Minister has undergone five comprehensive audits including a judicial decision that found no evidence supporting these allegations of misappropriated funds.