Whilst until the late 19th century most libraries were dependent on donations for their stock, since then donations have been insignificant for the majority of libraries in comparison with purchased acquisitions. There are organisations, however, which have considerable donations programmes and the Church of Scientology is a prominent example. Scientologists suggest that their donations of sets of the works of L Ron Hubbard are frequently ignored and discarded without due consideration. They adduce information regarding the response to donations made to libraries in Germany and France to support this suggestion. Furthermore, they cite the principle of freedom of expression as a rationale for the inclusion of Scientology material in library stock. The relevance of freedom of expression in the matter of donations is assessed in relation to established library principles relating to balanced and representative collections. The importance of clear policies on collection development, derived from a respect for freedom of expression, is stressed as a basis for reasoned explanations to donors of why their donations might be accepted or rejected.