The research collects and studies the Hadiths related to condemning illegitimate children, and it attempts to establish their reliability. It is meant to defend Islam in general, and the Sunnah in particular, to refute false anti-Islamic claims and to remove harmful implications for illegitimate children as well as society. The research adopts a critical inductive approach. The collection of Hadiths carefully considers relevance, proper documentation, critical Hadith procedures, application of Hadith critical evaluation requirements, as well as Hadith status in terms of "weak" and "sound" ranks. The research shows that all the Hadiths on condemning illegitimate children are reprehensible, weak or fabricated, and that they contradict Qur'anic teachings. It also shows that attempts to rank the Hadiths in question as sahih "sound" are faulty. Besides, the condemnation of illegitimate children may have been borrowed from Jewish and Christian sources, and then attributed to the Hadith. Jewish literature states that an illegitimate child cannot be absorbed into God's community except in the tenth generation.