Down syndrome is the most common cause of autosomal abnormality and mental retardation. The main purpose of this phenomenological research was to examine the meaning to pregnant women of positive results on maternal serum screening for Down syndrome, and their experiences of decision making on amniocentesis. The researcher interviewed seventeen pregnant women who showed positive results on maternal serum screening for Down syndrome. The participants were interviewed and audiotaped in an open-ended, non- structured and unguided way. Giorgi’s qualitative method of phenomenology was used to analyze collected data. The major findings of this research were that six essential concepts emerged as follows: (1) myths of screening result, (2) seeking behavior, (3) attainment of maternal tasks, (4) swing of decision making, (5) traditional women’s shackles, (6) traditional concept of fate. Thoroughly understanding the lived experiences of these pregnant women can enable nurses to design appropriate genetic counseling according to clients’ needs.