Previous studies show high agreement between MIC spectrophotometric readings and visual inspection of azoles and amphotericin B against Aspergillus fumigatus isolates. Here, we tested and compared the activity of a novel antifungal, olorofim, against Aspergillus spp., spp., and Lomentospora prolificans by visual inspection and spectrophotometric readings. Clinical isolates of Aspergillus ( = 686) and ( = 36) spp. and ( = 13) were tested. Olorofim MICs were evaluated-following the EUCAST E.Def 9.4 procedure-by visual inspection or spectrophotometric readings (combinations of either ≥90% or ≥95% fungal growth inhibition endpoints compared to drug-free control endpoints and different wavelengths [405 nm, 450 nm, 492 nm, 540 nm, and 620 nm]). We observed high activity of olorofim against all tested Aspergillus spp. (MICs up to 0.06 mg/L), except for A. calidoustus, and against and spp. (MICs up to 0.125 mg/L). The combination of ≥90% fungal growth inhibition endpoints at wavelengths of ≥492 nm resulted in high essential agreements with A. fumigatus and lesser agreement with non- Aspergillus, spp., and , although the number of isolates studied was low. This single-center study shows high agreement among olorofim MICs against A. fumigatus by visual inspection and spectrophotometric readings (≥90% fungal growth inhibition endpoints and wavelengths of ≥492 nm) and encouraging results against non- Aspergillus spp., spp., and .