Blackberry (Rubus fruticosus L.) is a perennial plant and belongs to the Rosaceae family and the genus Rubus. It is rich in minerals, vitamins, antioxidant vitamins and fibers that are very effective in the prevention of many diseases. Except in raw and frozen form, it can be consumed in the form of juices, jams, jelly, wines and liqueurs. During breeding, blackberry is attacked by various harmful organisms (pathogens, pests and weeds). In order to achieve a quality and quantity yield, it is necessary to monitor the occurrence and to timely and successfully suppress harmful organisms in the plantation. Diseases that can occur on blackberry are orange and violet rust, blackberry cane and leaf rust, purple blotch of blackberry, anthracnose and very common gray mold. Blackberries are attacked by pests such as aphids, raspberry cane midge, raspberry beetle and blackberry mite. Since it is a perennial fruit species, weeds typical of orchards and vineyards grow in the plantation. The aim of this final work was to monitor the occurrence of harmful organisms and to present the measures taken to protect the blackberry plantation in the Matija Antun Reljković High School in Slavonski Brod. The variety of Thorenfree blackberry is represented by about 70 % and Boysen 30 % is grown on a surface of 1.15 hectares. In the year 2018, in the blackberry plantation, they appeared anthracnose, blackberry cane and leaf rust, purple freckle and gray mold. Pests were not found, and present weeds were controlled by mulching and hilling. Blackberry care was based on proper pruning, foliar fertilization and small number of treatments with protective agents. A satisfactory yield was achieved.