The book contains the following chapters: I. Introduction, II. General characteristics of halictid bees, III. Study on halictids in Poland, IV. Halictid fauna of Poland: illustrated keys, characteristics of taxa. The morphology of the Halictidae is described, and some terms are discussed. A synopsis of classification this family is given. Phylogenetic relationships between its members are shown. An analytical account of bionomics of halictids is made, including various kinds of social life. On the basis of the study of the main entomological collections of institutions as well as private ones and original data, the Polish fauna of non-parasitic halictids is established. It includes 81 species belonging to 10 genera: Dufourea (4 species), Rhophitoides (1), Rophites (3), Systropha (2), Nomiapis (2), Nomioides (1), Halictus (6), Seladonia (6), Lasioglossum (13), Evylaeus (43). 3 species are recorded from Poland for the first time: Seladonia gavarnica (PÉR.), Evylaeus marginellus (SCHCK.), and E. obscuratus (MOR.). The occurrence in Poland of the following rare species is corroborated by new data: Dufourea halictula (NYL.), Rophites algirus PÉR., R. hartmanni FRIESE, Nomiapis femoralis (PALLAS), Seladonia semitecta (MOR.), Lasioglossum prasinum (SM.), Evylaeus brevicornis (SCHCK.), E. convexiusculus (SCHCK.), E. cupromicans (PÉR.), E. glabriusculus (MOR.), E. euboeensis (STR.), E. intermedius (SCHCK.), E. limbellus (MOR.), E. minutulus (SCHCK.), E. nigripes (LEP.), E. nitidulus (F.), E. quadrisignatus (SCHCK.), E. semilucens (ALFK.), E. setulellus (STR.), E. setulosus (STR.), E. tarsatus (SCHCK.), E. tricinctus (SCHCK.). All the species recorded from Poland and also 14 species that can be found in this country (rather in its south-eastern part), are characterised in this book in distributional, ecological and bionomical aspects. The distribution of halictids within the country is mapped and analysed. The zoogeographical status of the Polish halictid fauna against the background of the European and the Palaearctic faunas is described. Trophic links of halictid bees with flower plants, their biotopic preferences, abundance and phenology in Poland are presented. Original illustrated keys for identification of Polish halictids have been created.