Acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) are enzymes from the group of cholinesterases whose inhibition may have beneficial effects in the treatment of Alzheimer's disease. Inhibition of AChE and BChE increases the concentration of the neurotransmitter acetylcholine in the synaptic cleft which leads to the improvement of cognitive functions in patients. It is therefore not surprising that both enzymes are therapeutically interesting targets for alleviating the symptoms of Alzheimer’s disease. Glutathione S-transferase (GST) is an enzyme whose expression is increased in cancer cells, and inhibitors of GST represent potential antitumor agents. In the last years, ruthenium compounds have been investigated for their promising antitumor and antimetastatic capabilities. In previous studies, ruthenium complexes have shown good anti-AChE activity and anti-GST activity and possible therapeutic applications in the treatment of Alzheimer’s disease and cancer, where they can act as multitarget drugs. Therefore, we have tested 32 newly synthesized ruthenium complexes and their precursors for inhibition of the above mentioned enzymes. Results of this study have shown that ruthenium complexes have good inhibitory activity on enzymes, moreover some of the complexes have inhibited all of the three tested enzymes, which makes them potential multitarget drugs. Good anti-AChE activity is shown in 15 complexes, anti-BChE activity in 14 complexes, and anti-GST activity in 4 of the complexes. Complex worth mentioning is JKZU13-08 which exhibited strong inhibitory activity on all of the three tested enzymes. This study has opened the possibility for further testing of ruthenium complexes as potential drugs.