Ibn Yunus' importance in the history of astronomy stems mainly from this work, which is a particularly fine example of this class of astronomical handbook, the compilation of which concerned most Islamic astronomers. Ibn Yunus' Hakimi Zij is distinguished from other surviving zijes in that it begins with a list of observations, made by both Ibn Yunus and some of his predecessors. In many respects his astronomical works have a modern appearance; many of the parameters which he used in his Zij are much superior to those of his predecessors and he is also known for his meticulous calculations and attention to detail. For example, where applicable his calculations took into account the atmospheric refraction of the Sun's rays at the horizon, and his figure of forty minutes of arc between the observed and 'true' (level) horizon is probably the earliest specific figure recorded for this quantity. His observations are considered so reliable that some of the thirty eclipses reported by him were used by Simon Newcomb in the nineteenth century, in determining the secular acceleration of the moon.
Ibn Yunus was renowned as a poet, and has been associated with some large instruments. One was an armillary sphere with 9 rings, each of which weighed 2,000 pounds, and was large enough for a horseman to pass through, and the other was a copper instrument resembling an astrolabe, three cubits across. However, both associations are uncertain.