The United Kingdom has enacted a series of legislation against terrorism. Some of the legal measures adopted under the UK’s Terrorism Act of 2000 & 2006 include the powers to identify and ban terrorist groups and powers to criminalise statements that encourage the commission or preparation of acts of terrorism. This article therefore attempts to appraise the provisions of the UK Terrorism Act 2000 & 2006 on proscription of terrorist organisations and encouragement of terrorism. The aim is to explore whether these provisions are consistent with UK’s human rights obligations, especially under the ECHR. The article argues that although the State’s powers to identify and ban terrorists groups and to outlaw statements that encourage terrorism are legitimate counterterrorism measures, nevertheless there are human rights concerns that fundamental liberties such freedom of expression including freedom of speech and the press, or the right to privacy, may be infringed upon unnecessarily under the guise of countering-terrorism. Similarly, without proper safeguards, the State’s powers to proscribe an organisation under the Act raises concerns about the right to assembly and freedom of association. This article argues further that there is a need for a proper balance between legitimate security interests and the protection of fundamental rights. For instance, the proscription of an organisation should not be the end, there should be a biennial or periodic parliamentary review of the proscribed organisations.