Marshall competed in the 100 m, 200 m and 4 × 100 m Relay. Her best result was anchoring the U.S 4 × 100 m relay team to the gold medal at the 1987 World Championships Rome Italy, in a time of 41.58 CR which still ranks as one of the fastest times ever.
She clocked an impressive 10.11 for her final 100 m which saw her bring the team home almost half a second ahead of the GDR team anchored by Marlies Göhr (10.41 secs). Pam came 8th in the 100 m and fourth in the 200 m at the same Championship.
