Springs represent specific habitats on the border of ground and surface waters in which we can find very diverse and unique communities of macroscopic invertebrates. Research of macroscopic invertebrate communities was conducted in 15 karts springs in Croatia, during April and June 2011. Aim of this study was to determine composition and structure of the macroscopic invertebrate communities in studied springs and to establish effects of physico-chemical and structural features of springs on macroinvertebrate communities composition. Qualitative samples of macroscopic invertebrates were taken on different types of substrate using hand nets and then preserved in 75% ethanol. Physico-chemical factors (water temperature, oxygen concentration and saturation, conductivity and pH) were measured using WTW probes. Invertebrates extracted from the collected samples were divided into higher systematic categories and total number of individuals was determined for each category. Altogether, 37791 specimens from 16 systematic categories of macroscopic invertebrates were found, with Amphipoda and Gastropoda being most abundant at most springs, as well as 8 insect orders and 8 other systematic categories. Karst springs as natural laboratories, represent excellent habitats for studies of macroinvertebrate ecology. Since by many endangered and rare invertebrate species inhabit karst springs, these important and special habitats should be protected from negative human impact.