Uterine fibroids are benign tumours, which are associated with subfertility and early pregnancy loss. This study was carried out to examine the effect of submucous fibroids on concentrations of glycodelin, insulin-like growth factor binding protein-1 (IGFBP-1), interleukin-6 (IL-6), interleukin-10 (IL-10), tumour necrosis factor α (TNFα) and osteopontin in uterine flushings. Premenopausal women with a certain diagnosis of submucous fibroid confirmed on three-dimensional saline infusion sonohysterography were recruited into the study. The control group included women without ultrasonic evidence of any uterine or endometrial pathology. All women had uterine flushings performed 7days post LH surge. Enzyme linked immunoassays were performed to analyse glycodelin, IL-6, IL-10, TNFα and osteopontin, whilst immunoradiometric assay was used to analyse IGFBP-1. In 23 women with submucous fibroids, the concentrations of glycodelin and IL-10 in uterine flushings were significantly lower compared with 17 women in the control group (P=0.002; P=0.007, respectively). There were no significant differences between the two groups in concentrations of IGFBP-1, IL-6, TNFα and osteopontin. Women with submucous fibroids had significantly lower concentrations of glycodelin and IL-10 in mid-luteal phase uterine flushings. This finding may explain the association with submucous fibroids and adverse reproductive outcomes. Uterine fibroids are small growths from the muscle of the uterus (womb). Submucous fibroids protrude into the cavity of the womb. We do not know what causes fibroids to form and grow. In most women, fibroids cause no symptoms and they are sometimes detected on routine gynaecological examination. In some women, however, fibroids can cause heavier and longer menstrual periods. Another problem associated with fibroids is bleeding between periods. The effect of fibroids on fertility is not clear, but some doctors believe that they may also cause infertility and early miscarriage. This study tried to see whether presence of submucous fibroids has any effect on various substances produced by the lining of the womb to facilitate development of early pregnancy. Women with a confirmed diagnosis of submucous fibroids were asked to attend the clinic and have the uterine cavity flushed with a special solution 7days after ovulation. The fluid, which was taken back from the womb, was then analysed to measure the amounts of substances that favour pregnancy development. Women with a normal uterine cavity were also asked to have the uterine cavity flushed to act as a comparison. The study showed that the uterine cavities of women with submucous fibroids were producing decreasing amount of substances favourable to early pregnancy development. We speculate that this may explain why some women with submucous fibroids have difficulties falling pregnant. Our findings should be helpful to doctors advising women with submucous fibroids who wish to start a family.