We aimed to develop and validate a Loop-mediated Isothermal Amplification (LAMP) assay to Sporothrix brasiliensis. LAMP reaction was developed using six primers designed based on calmodulin gene. In the LAMP reaction, we tested twenty isolates of S. brasiliensis from animals and humans, along with ten tissue samples extracted from the left footpad of mice that had been experimentally infected with S. brasiliensis. In addition, it included DNA samples from various other fungal species for specificity evaluation. All S. brasiliensis isolates yielded positive results in the LAMP, and the limit of DNA detection was 1 ng/μL. All murine samples were positive in the test while DNA from other fungal species were all negative, resulting in 100% of sensitivity and specificity of primers. LAMP diagnosis technique is a promising alternative to sporotrichosis diagnosis, in a simple and cost-effective way. Further studies are warranted to validate this technique using animal model samples obtained from both humans and animals.