The development and application of a high throughput aqueous solubility assay is reported. Measurements for up to 637 compounds can be made in a fully automated experiment. Results from this assay were used to quantify risk of unacceptable solubility as a function of lipophilicity for neutral fragment-like compounds. Assessment of risk of unacceptable solubility was combined with experimental solubility measurement to select compounds for inclusion in a fragment-screening library.