Born in Hořice, Jehličková established herself at national level in the mid-1960s in the 800 m, which was then the longest distance regularly by women. She won the Czechoslovak Athletics Championships in 1966, then again in 1968. This earned her her debut at the 1968 Mexico City Olympics, where she was a semi-finalist. The longer 1500 m was introduced as a championship event for the 1969 European Athletics Championships—the first time the women's race was incorporated at a major international event—and it began to be contested more widely. Jehličková became the first Czechoslovak national champion in the 1500 m, and she also defended her 800 m title.