Leishmania infantum nicotinamidase, encoded by the Lipnc1 gene, converts nicotinamide into nicotinic acid to ensure Nicotinamide–Adenine–Dinucleotide (NAD⁺) biosynthesis. We were curious to explore the role of this enzyme during L. infantum development in its natural sand fly vector, Phlebotomus perniciosus (Diptera, Phlebotominae), using null mutants with a deleted Lipnc1 gene. The null mutants developed as well as the wild type L. infantum at the early time points post their ingestion within the blood meal.