--- - |2 Summary This study aimed to ascertain if atropine is useful for suppressing the pain suffered during four‐dimensional hysterosalpingo‐contrast sonography (4D‐HyCoSy) when assessing infertility in women. A total of 252 patients were divided into 2 groups to receive or not receive atropine (0.5 mg) injection 30 minutes before 4D‐HyCoSy. Pain was evaluated using a numerical rating scale (NRS): during 4D‐HyCoSy; upon 2‐dimensional transvaginal sonography; before catheter insertion; upon insertion and fixation of the catheter into the uterine cavity; 30 minutes after 4D‐HyCoSy. According to the degree of patency of Fallopian tubes, the 6 patterns observed were integrated further into 3 patient groups: all‐negative (both Fallopian tubes were negative), positive‐and‐negative (one Fallopian tube showed patency and the other showed stenosis or non‐patency), and all‐positive (both Fallopian tubes showed stenosis or non‐patency). We compared the NRS scores and prevalence of side‐effects other than pain between the atropine‐injection and non‐atropine‐injection groups within the three groups mentioned above. The NRS score showed no significant differences among the groups at any time point (all P > .05). The different prevalence of side‐effects other than pain was significant between the atropine‐injection and atropine‐non‐injection groups (P = .012). These data suggest that atropine does not reduce pain in patients during 4D‐HyCoSy. However, atropine may reduce the prevalence of other side‐effects during 4D‐HyCoSy, which needs a further, large, prospective, multi‐cohort study to verify. - 'Clinical and Experimental Pharmacology and Physiology, Volume 45, Issue 12, Page 1334-1340, December 2018. '