She started her career in
AVM Studios where she was one of the resident playback singers along with T. S. Bagavathi. Her very first song was
Maiyal Migavum Meerudhe in the film
Vijayalakshmi produced by Pragathi Pictures, the forerunner to
AVM Studios. During the 1940s, she sang for almost all the films produced by AVM before continuing her work independently. In later years, she was a popular voice for child artists. Films such as
Kaveriyin Kanavan,
Kaithi Kannayiram and
Engal Selvi are the earlier ones where she recorded her voice for child artists. Since 1964 till the 1990s she was only sought for playback for child artists. She was the first playback singer for
Kamal Haasan for the song
Ammaavum Neeye Appaavum Neeye in
Kalathur Kannamma when she was offered by
AVM Studios after a break. Rajeswari had recorded many songs for Baby
Shamili. Her voice suits the best when Shamili was a child artist in
Dhurga,
Lakshmi Dhurga, Bhairavi,
Sendhoora Devi, Sindhoora Devi, Thai Poosam, Sivasangkari, Dheiva Kuzhandhai and Sivarathiri.
Music composers she sang for She started her career in
AVM Studios under
R. Sudarsanam’s music. Later, many of her songs are under
K. V. Mahadevan's music direction. In the late 1980s and early 1990s,
Shankar–Ganesh engaged her often.
Playback singers she sang with She sang immemorable duets mostly with
T. M. Soundararajan. Others include
Seerkazhi Govindarajan,
A. M. Rajah,
Thiruchi Loganathan, V. J. Varma, K. Devanarayanan,
V. N. Sundaram,
A. L. Raghavan,
S. C. Krishnan, M. Satyanarayana,
Madhavapeddi Satyam,
Ghantasala, K. Appa Rao,
K. J. Yesudas,
S. P. Balasubrahmanyam &
Mano. She also sang duets with female singers, most notably with T. S. Bagavathi. Others are
L. R. Eswari,
K. Jamuna Rani,
P. Susheela,
Radha Jayalakshmi,
R. Balasaraswathi Devi,
A. P. Komala,
S. Janaki,
K. S. Chithra,
Swarnalatha, U. R. Chandra, L. R. Anjali,
N. L. Ganasaraswathi,
K. Rani,
Santha P. Nair & Kalyani.{{cite web|url=http://www.indian-heritage.org/flmmusic/msrajeswari.html The singing actors she sang with were
K. R. Ramasamy &
T. R. Ramachandran. ==Death==