Astrology, horoscopes, superstition and fortune-telling are all actions of jaahiliyyah (ignorance) which Islam came to show as false and to explain that they are shirk, because they involve depending on something other than Allaah and believing that benefit and harm come from something other than Him, and believing the words of fortune-tellers and soothsayers who falsely claim to have knowledge of the unseen in order to cheat people of their money and change their beliefs.
The evidence (daleel) for that is the hadeeth narrated by Abu Dawood in his Sunan with a saheeh isnaad from Ibn ‘Abbaas (may Allaah be pleased with him), that the Messenger of Allaah (peace and blessings of Allaah be upon him) said: “Whoever learns anything of astrology has learned a branch of witchcraft (al-sihr)…” And al-Bazzaar narrated with a jayyid isnaad from ‘Imraan ibn Husayn that the Messenger of Allaah (peace and blessings of Allaah be upon him) said: “He is not one of us who practises augury or has it done for him, who tells fortunes or has his fortune told, or who practises witchcraft or has that done for him.” Whoever claims to know some matter of the unseen either is a fortune-teller or is acting like a fortune-teller in some sense, because Allaah is the only One Who has knowledge of the unseen. Allaah says (interpretation of the meaning);
“Say: ‘None in the heavens and the earth knows the Ghayb (Unseen) except Allaah…’”
My advice to everyone who has anything to do with these matters is to repent to Allaah and ask for His forgiveness, and to depend only on Allaah and to put their trust in Him in all their affairs, whilst following the practical means that are prescribed or permitted in sharee’ah. They should give up these matters of jaahiliyyah, keep away from them and avoid asking the people who practise them or believe what they say, out of obedience to Allaah and His Messenger (peace and blessings of Allaah be upon him), and in order to protect his commitment to Islam and his ‘aqeedah (religious belief).
Adapted from Majmoo’ Fataawa Shaykh Ibn Baaz (may Allaah have mercy on him), 2/123