The Author presents legal basis of unworthiness of inheritance in polish law of inheritance. At the beginning the Author explains the term of ‘inheritance’ as passing all of property rights and obligations included in inheritance on one or more heirs. Polish law provides two sources of the appointment of inheritance: act and will. The Author shows entities who do not inherit because of the reason of unworthiness. In the civil cod e there is indicated that the unworthiness of inheritance does not happen by law but under a court’s decision. The civil code does not specify in which procedure the court orders the unworthiness, however the judicature decisions of the Supreme Court does it – in process. The legal grounds to the unworthiness of inheritance are indicated in the article 928 § 1 of the civil code. In the first place the legislator points out the felony with an intentional guilt against the testator. The Author emphasizes that everyone who has an interest can b ring the statement of claim.