The dataset contains disease survey data for Scots pine trees in a long-term progeny-provenance common garden trial planted in three sites in Scotland. Trees were originally collected from 21 provenances of native Caledonian pinewood from across the native range in Scotland. Disease surveys were performed annually between August and September from 2015 to 2025 (excluding 2019 and 2020) for one site (FS) and in 2016 and 2022 for two sites (FE and FW). Susceptibility to Dothistroma needle blight (DNB, caused by Dothistroma septosporum) for each tree was estimated by recording two traits: 'direct susceptibility' (estimated percentage of needles with lesions) and 'indirect susceptibility' (estimated years needle retention). Indirect susceptibility was recorded to ensure needle loss associated with susceptibility to DNB was also captured. In addition to annual measures of susceptibility, long-term susceptibility was also estimated for each tree. Full details about this dataset can be found at https://doi.org/10.5285/c3b45aac-a497-4e57-9ee0-8cdd8677f5de