In 1981 she joined the Euskadi Symphony Orchestra since that fails to take to get little later in the National Orchestra of Spain.
First flute for more than thirty years of this orchestra, Juana Guillem could interpreted the most important symphonic flute repertoire with such greats maestros as Kurt Sanderling, J. López Cobos , Walter Weller, Yuri Aronovich , A. Marbá Ros , E. Inbal , Yuri Temirkanov, Josep Pons and many others.
As a concert flutist has performed with: National Orchestra of Spain repeatedly, Orchestra Reina Sofia, Valencia Orchestra , Symphony Orchestra of Flandes, Cordoba Orchestra , Orchestra of the Community of Madrid, Cantabria Chamber Orchestra , Orchestra Joaquin Rodrigo, Spanish Chamber Orchestra, Municipal Band Harmony of Madrid and from Bilbao …...
Prestigious spanish composers have dedicated their works and commissioned premieres. She has recorded for EMI " Fantasy for a Gentleman " in flute version and the " Aria " for flute and orchestra by Joaquín Rodrigo. She has also recorded music for flute of most important valencian composers .
Parallel to the orchestra Juana Guillem acts with different sets of chamber music, covering many styles from Baroque to current music. Form Trio with bassoonist Enrique Abargues and pianist Anibal Bañados. It pays special attention to the repertoire of flute and percussion with her brother Juanjo Guillem. She has performed alongside performers like Nicolas Chumachenco Sergei Teslia, Youri Bashmet , Maxence Larrieu , Denis Pascal, Carmine Calabrese ……..
She is invited to the Conservatory of Palma de Mallorca and the Centre for Studies Neomúsica Madrid. She teaches courses throughout Spain and collaborates regularly in meetings of Youth Orchestras. She is also wolrking of professor of the High Centre Katarina Gurska, and in the university Alfonso X el Sabio in Madrid.
Recently she played in the last Spanish Convension of flute celebrated in Bilbao (Spain) interpreting the Concert for flute and Wind Orchestra of Mike Mower.