1990 Estoril Open
Date	2–8 April (men) 16–22 July (women)
Edition	1st(ATP) / 2nd(WTA)
Category	ATP World Series (men) Tier V (women)
Draw	32S/16D
Prize money	$225,000 (men) $100,000 (women)
Surface	Clay / outdoor
Location	Oeiras, Portugal
Venue	Estoril Court Central
Champions
Men's singles
Emilio Sánchez[1]
Women's singles
Federica Bonsignori
Men's doubles
Sergio Casal / Emilio Sánchez[2]
Women's doubles
Sandra Cecchini / Patricia Tarabini
← 1989 · Estoril Open · 1991 →

The 1990 Estoril Open was a combined men's and women's tennis tournament played on outdoor red clay courts. It was the first edition of the event Estoril Open for the men (the 2nd for the women), and was part of the ATP World Series of the 1990 ATP Tour. It took place at the Estoril Court Central, in Oeiras, Portugal, from 2 April through 8 April 1990 for the men's tournament and from 16 July through 22 July 1990 for the women's tournament. Emilio Sánchez and Federica Bonsignori won the singles titles.

Finals

Men's singles

Emilio Sánchez defeated Franco Davín 6–3, 6–1

• It was Sánchez's second singles title of the year, and the 11th of his career.

Women's singles

Federica Bonsignori defeated Laura Garrone 2–6, 6–3, 6–3

Men's doubles

Sergio Casal / Emilio Sánchez defeated Omar Camporese / Paolo Canè 7–5, 4–6, 7–5

• It was Casal's first doubles title of the year, and the 25th of his career.
• It was Sánchez's second doubles title of the year, and the 28th of his career.

Women's doubles

Sandra Cecchini / Patricia Tarabini defeated Carin Bakkum / Nicole Jagerman 1–6, 6–2, 6–3