In our previous study, we observed that hydrosalpingeal fluid (HSF) adversely effect mouswe embryo development and hatching. The aim of this study was to evaluate the effect of HSF as assessed by the blastocyst development rate (BDR) and by cell counting in vitro. HSF was collected from ninie patients undergoing salpingoneostomy to correct hydrosalpinx. Two-cell embryos were obtained from superovulated ICR mice. T6 medium and $T6{pm}0.4%$ bovine serum albumin were used as control media. T6 medium containing 10% or 50% HSF and 100% HSF from each patient were used as test media. Nine to 15 embryos were cultured in micro drops prepared from each of these media. To assess the total cell number within each blastocyst, the blastocysts were fixed and stained with Hoechst 33342 to facilitate cell counting. The mean BDR in two control media were 88.89% and 85.40%. The mean BDR in media containing 10%, 50%, 100% HSF were 85.87%, 89.58% and $75.57%^*$, respectively ($^*$: p<0.05). The overall mean cell count $({pm}SEM)$ in control media were $87.6{pm}9.65;and;90.12{pm}11.38$. The BDR was affected adversely only by 100% HSF and not in media containing 10% or 50% HSF. Mean cell counts were decreased significantly only in blastocysts cultured 100% HSF ($63.8{pm}13.66$; p<0.01) but not in blastocysts cultured in 10% or 50% HSF ($91.3{pm}12.44;and;82.9{pm}18.27$, respectively). Thus, it is concluded that HSF has no embyotoxic effect but has a mildly negatively effect on embryonic growth and development.