Nina graduated from the Lunacharsky Belarusian State Conservatoire (M.Liudvig’s class). In 1972 she joined the Belarusian State Philharmonic. She joined the Bolshoi opera company as a leading soloist in 1977 and was promoted to manager of the opera company in 2003. In 1984 she was awarded the title of the Honoured Artist of the Republic of Belarus.

Possessing a unique lyrical dramatic soprano, outstanding scenic charm and bright artistic talent, Nina Kozlova has created expressive images in such operas of classic and national repertoire as Donna Anna, Cherubino, Papagena (Don Giovanni,  Le nozze di Figaro, The Magic Flute by Wolfgang Amadeus Mozart), Berta (The Barber of Seville by Gioachino Rossini), Elisabeth, Leonora, Aida and Amneris, Amelia, Anna  (Don Carlos, Il trovatore, Aida, Un ballo in maschera, Nabucco by Giuseppe Verdi), Mercedes (Carmen by Georges Bizet), Cio-Cio San (Madama Butterfly by Giacomo Puccini), Giulietta (Les contes d'Hoffmann by Jacques Offenbach), Nedda (Pagliacci by Ruggero Leoncavallo), Innkeeper (Boris Godunov by Modest Mussorgsky), Tatyana, Liza, Iolanta (Eugene Onegin, The Queen of Spades, Iolanta by Pyotr Tchaikovsky), Kupava, Saburova (The Snow Maiden, The Tsar’s Bride by Nikolai Rimsky-Korsakov), Natasha Rostova (War and Piece by Sergei Prokofiev).  Nina performed roles in a number of premiere opera productions of contemporary Belarusian composers including Klava (Life Path by Henry Wagner), Kobi, Paola (The Lady’s Visit, Giordano Bruno by Sergey Kortes), Irina (Grey Legend by Dmitry Smolsky), Nastya (The New Land by Yury Semeniako), took part in radio recording of the operas Kastus Kalinouski by Dmitry Lukas and Mutter Courage by Sergey Kortes.