We created a dataset - the Lifetime From Intensity (LFI) dataset - that is dedicated to estimate the lifetime from intensity images. The dataset consists of 156 real fluorescence microscopy images obtained with custom-built two-photon microscope and representative biological zebrafish samples. We use 140 images for training and 16 images for testing. These images are captured with 2 different excitation wavelengths (800 and 920 nm) and different power levels (5 mW and 8 mW).