Atropine, fentanyl, and its analogues are used simultaneously for medical purposes as anesthesia during surgeries. Even at low doses, atropine has a paralyzing effect; and at relatively higher doses, it stimulates the central nervous system, causing euphoria, excitation, and hallucinations. Atropine, fentanyl (FL), and its analogues have one feature in common, i.e., very strong action, such that overdosing is frequent. Data on the abuse of FL and its analogues indicate that these compounds are becoming increasingly popular on the drug market. On the drug market, FL and its many analogues are sold as China White, Fentanyl, Synthetic heroin, Mexican Brown, Persian White, Apache, China Girl, Dance Fever, Friend, Goodfella, Jackpot, Murder 8, TNT, and Tango and Cash. All of these compounds have a much stronger effect on the human organism than morphine. Since producers of these drugs for the illegal drug market are not certain of the exact composition of the preparations they produce, they may contain various active compounds with varying strengths of effects. Abuse of FL and its derivatives in Poland is not yet a significant problem; however, the growing popularity of FL is confirmed by the increasing amount of “disappearances” from drug stores and healthcare institutions and issues in their dosage, which can be found on the Internet. In Poland, the Act on Counteracting Drug Addiction classifies FL and its analogues as narcotics in the I-N group, which means that possession and distribution of these substances is illegal. 2 figures, 1 table, and 25 references