1976–1978: Junior career

Simonsson won the Swedish Junior Indoor champion in 1976 as a 16 year old and in 1977 and 1978 the Swedish Junior Outdoor Champion.^[4] He played in his first Junior Grand Slam event at Wimbledon in 1977 and made his debut in a senior tournament at the Swedish Open.^[5][6]

1979–1981

In 1979, Simonsson reached the quarterfinals at the challenger event in Biarritz and he reached the same stage in Brussels and Taipei on the Grand Prix circuit. His best result in 1979 was making the semifinals in Tel Aviv. In doubles and with partner Per Hjertquist, he reached the semifinals in Brussels.^[4] Simonsson also made his Davis Cup debut for Sweden during July 1979 in the Europe Zone B, semifinals against Romania.^[7]

Simonsson started the 1980 season by competing on the challenger circuit, and in May, he reached the final at the Galatina Challenger. On the Grand Prix tour, he made the quarterfinals at Florence and the semifinals in Munich. In doubles, he reached two semifinals, with Hjertquist at Bordeaux and with his brother, Hans in Madrid.^[4] Simonsson represented Sweden during the 1980 Davis Cup, playing in both the singles and doubles.^[7]

In August 1981, Simonsson won his first titles on the challenger circuit when he captured both titles at the Le Touquet Challenger. In the singles, he defeated Georges Goven in the final and in the doubles, he teamed with compatriot Anders Järryd to win the title. Earlier in the year, he played in the singles final at the Torino challenger and with Järryd in the doubles final at the Royan challenger.^[4]

1982–1983

During May 1982, Simonsson made his first final on the Grand Prix tennis circuit at the tournament in Florence, where he lost in three sets to the world number 9 Vitas Gerulaitis. His other notable achievements of 1982 were two quarterfinals in Guarujá and in Toulouse.^[8] In February 1983, Simonsson reached the semifinals in Caracas and in the same month, he reached the quarterfinals at the Cairo Challenger. During the first three weeks of May, he made three semifinals, first at the Parioli Challenger, thereafter at Florence and at the Italian Open in Rome. After his performance during May, he broke into the top 50 in the world rankings for the first time. Simonsson played in two quarter-finals in 1983 at Båstad and Bordeaux.^[4]

At the Bordeaux Open he was successful in the doubles and won his first Grand Prix title with fellow Swede Magnus Tideman. In November and alongside Stanislav Birner, he played in his second doubles final at Ferrara, and the following week, he and Jan Gunnarsson reached the semifinals in Toulouse.^[8]

1984–1986

The 1984 season was less successful, with only one quarterfinal at Florence during May. In doubles, he made three semifinals: in Metz and Cologne, with Hjertquist and in Palermo with Ronnie Båthman.^[4]

In July 1985, Simonsson teamed with his brother and reached the semifinals at Båstad, and they won the doubles title in Hilversum, his second Grand Prix doubles title. Simonsson had one doubles semifinal at Florence with Mike De Palmer. In singles, he made one quarterfinal at Båstad.^[4] In 1986, Simonsson reached one quarterfinal on the Challenger Tour at Marrakesh, and he played his last singles match at Kitzbühel, losing in the first round.

Singles: 1 (1 loss)

Result	W/L	Date	Tournament	Surface	Opponent	Score
Loss	0–1	1982	Florence, Italy	Clay	Vitas Gerulaitis	6–4, 3–6, 1–6

Doubles: 3 (2 wins, 1 loss)

Result	W/L	Date	Tournament	Surface	Partner	Opponents	Score
Win	1–0	1983	Bordeaux, France	Clay	Magnus Tideman	Francisco Yunis Juan Carlos Yunis	6–4, 6–2
Loss	1–1	1983	Ferrara, Italy	Carpet	Stanislav Birner	Bernard Mitton Butch Walts	6–7, 6–0, 3–6
Win	2–1	1985	Hilversum, Netherlands	Clay	Hans Simonsson	Carl Limberger Mark Woodforde	6–3, 6–4

Singles: 1 (0–1)

Result	Year	Tournament	Surface	Opponent	Score
Loss	1978	US Open	Hard	Per Hjertquist	6–7, 6–1, 6–7

Singles: (1)

No.	Date	Tournament	Surface	Opponent	Score
1.	Aug 1981	Le Touquet, France	Clay	Georges Goven	6–2, 6–1, 7–5

Doubles: (1)

No.	Date	Tournament	Surface	Partner	Opponents	Score
1.	Aug 1981	Le Touquet, France	Clay	Anders Järryd	Miroslav Lacek Libor Pimek	7–5, 7–5