Background: De qi, the needling sensation, is important in acupuncture treatment. Almost all studies believe that deep needling and manipulation could achieve a significant de qi sensation. However, relatively few studies have examined the effect of psychological factors on de qi, and those that did often reached different conclusions. Objectives: To explore the influence of psychologic factors on de qi in patients with primary dysmenorrhea (PD). Methods: Sixty-eight PD patients with cold and dampness stagnation were randomly allocated to de qi (deep insertion using thick needles, with manipulation, n=17) and non-de qi groups (shallow insertion using thin needles, without manipulation, n=51). Both groups received bilateral needling at Sanyinjiao (SP6) for 30 min. De qi was assessed using the Acupuncture De qi Clinical Assessment Scale (ADCAS). The patients' acupuncturerelated anxiety and their expectations of the relationship between needle sensation and curative effect were evaluated using a five-point and four-point scale, respectively. Results: Within the de qi group, all patients experienced the de qi sensation, although anxiety levels were unrelated to de qi. Patients' expectations correlated negatively with de qi timing, and positively with electric sensation. Within the non-de qi group, 59.5% of patients experienced de qi. Between those who experienced it and those who did not, no significant differences were found in anxiety levels, although patients' expectations differed significantly. Among patients who experienced de qi sensations in the non-de qi group, anxiety and throbbing were positively correlated. Additionally, patients' expectations correlated positively with de qi intensity, as well as coldness, and numbness. Conclusion: Psychological factors should be considered when studying de qi since PD patients' expectations could influence the de qi sensation at SP6.