Leaf area index (LAI) measurements acquired during the SMAP Validation Experiment 2016 in Manitoba (SMAPVEX16-MB) field campaign were used to validate LAI estimates from Sentinel-2/MSI data using The Simplified Level 2 Product Prototype Processor (SL2P) processor and LAI estimates obtained from locally calibrated vegetation indices (VI) models. Results showed that performances of LAI/SL2P estimates (RMSE = 0.98, bias = -0.37, slope = 0.70), when compared to in-situ data, are lower than performances of LAI/VI estimates (RMSE = 0.38, bias = 0.19, slope = 0.75) when compared to the same in-situ data.