She showed early promise and won the unofficial national youth championships, Colgate Cup, at three different levels, as a 12, 14, and 16-year-old.

Neumann has later given a lot of credit, for her successful career, to her local coach since her early years, Pierre Karlström.

She bettered her personal 72-hole best with 30 strokes and beat the whole Swedish amateur national team, some of whom had not even heard of Neumann before the tournament.

After another appearance at the Espirito Santo Trophy in Hong Kong in late 1984, she turned professional at the beginning of 1985, not yet 19 years old.

At the Höganäs Ladies Open at Mölle Golf Club in Sweden, she became the youngest ever winner on the WPGA Tour.

She led the 1986 Ladies European Tour Order of Merit for most of the season, with eight straight top three finishes, but lost the lead to Laura Davies at the last tournament, the Spanish Open.

The same year the ladies' Swedish Golf Tour get started with seven tournaments and Neumann was its first Order of Merit winner.

This accomplishment was later also achieved by Alison Nicholas, Pak Se-ri, Karrie Webb, Inbee Park and Ariya Jutanugarn.

Neumann played in the European Solheim Cup team against United States, six times in a row, 1990, 1992, 1994, 1996, 1998, and 2000.

On 7 June 2006, the Ladies European Tour announced that Neumann has earned Lifetime Membership of the LET, at the time a feat achieved by six other golfers, Helen Alfredsson, Laura Davies, Marie-Laure de Lorenzi, Alison Nicholas, Dale Reid and Annika Sorenstam.