The POLEX Polish Lexicon is a morphological dictionary of Polish language. It comprises about 100,000 entries. The POLEX dictionary includes the core Polish vocabulary of general interest. It is based on a precise machine-interpretable formalism (coding system), the same for all categories (classes of speech). The dictionary entries are of the following form: BASIC_FORM+LIST_OF_STEMS+PARADIGMATIC_CODE+DISTRIBUTION_OF_STEMS The paradigmatic code (= inflection code) contains full paradigmatical information, in particular all inflection endings are encoded in an unambiguous way. For example the dictionary items for the nouns frajerI and frajerII are as follows: frajer; frajer, frajerz; N110; 1;1-5,9-13;2:6-8,14 frajer; frajer, frajerz; N110; 1;1-5,8-14;2:6-7 The basic form (frajer) is followed by the list of stems (frajer, frajerz). The following inflection code (N110) describes the complete list of endings for all paradigmatic positions (here from 1 to 14). These endings are: (_,a,owi,a,em,e,e,y,ów,om,ów,ami,ach,y). The distribution of stems associates stems to the paradigmatic positions. E.g., the distribution 1:1-5,8-14;2:6-7 says that all but two positions (singular locative and singular vocative) are associated with the first stem (frajer), whereas the remaining two are associated with the second one (frajerz). Provided the table of endings, generation of all the inflected forms is straightforward (and the same for all words of the POLEX dictionary). Dictionary files are in basic ASCII format. Specific Polish characters (ą, ę,…, ż, ź) are represented by the corresponding ASCII letters and the single or dubbled (for ź only) tilde ~ (a~, e~,…,z~, z~~). For example, “król” is represented by “kro~l” and “łabądź” by “l~aba~dz~~”. The resource contains: - more than 42,000 nouns, - more than 12,000 verbs, - more than 15,000 adjectives, - more than 25,000 participles, - about 200 pronouns. A simple lemmatiser (in form of PROLOG prototype) is also included.