Walcher was from Lotharingia and came to England about 1091. He is noted for using an astrolabe to measure the time of several solar and lunar eclipses with an accuracy of about fifteen minutes. Using his early observations, he computed a set of tables giving the time of the new moons from 1036 through 1111, which he considered to be important for purposes of medical astrology. His later observations revealed significant errors in his tables, reflecting the limitations of early medieval astronomical theory.
In one of his later writings, which drew on Arabic astronomy received from Spain, he recorded angles in degrees, minutes, and seconds, although he wrote these numbers using Roman, rather than Arabic numerals.
Walcher's gravestone in Malvern Priory Church records his abilities as an "able astrologist and mathematician". As head of the Priory he would have been a very influential figure in the county of Worcestershire.