BackgroundIn developing country like BANGLADESH, people depend more on pharmacies due to expediency, shorter waiting time, cost reduction, availability of credit and flexible opening hours. The aim of this study was to investigate medicines dispensing patterns of the pharmacies in RAJSHAHI, BANGLADESH and to identify and analyze contribution of drugsellers and quacks in irrational drug use.MethodsThis cross-sectional study was conducted during January 2016 - April, 2016 in 75 randomly selected private pharmacies including both licensed and unlicensed pharmacies of covering LAKSHMIPUR area.ResultDuring the whole study process, total 7944 clients visited the pharmacies under observation and 24,717 medicines were dispensed. 22.70% of all these drugs were sold without a prescription. Out of the 5610 items dispensed without prescription, 66.2% were dispensed on the request of clients themselves and 33.8% on the recommendation of a drug seller. Number of medicine in a prescription was highly variable ranging from 2 to 5 medicines per prescriptions (mean = 3.03). The average number of medicines dispensed from each of the pharmacies during the observation period was 392, varied pharmacy to pharmacy – ranging from 194 to 588. Lowest selling medicines were sedative and hypnotics and highest selling medicines were antimicrobials. The recommendation rate for antibiotics was highest for the quacks (26.48%) though the major amount of the antimicrobials (n = 3039, 65.83%) were dispensed on prescription. Macrolides, quinolones, metronidazoles and cephalosporins are most favourite drug of quacks, clients and pharmacists.ConclusionMajority of medicines were dispensed irrationally without any prescription and over the counter dispensing of many low safety profile drugs was common. The results and discussion presented in this paper will be helpful to provide a baseline to redirect further studies in this area.Electronic supplementary materialThe online version of this article (doi:10.1186/s12913-017-2072-z) contains supplementary material, which is available to authorized users.