After completing the basic medical degree (MD, Hons) in Slovakia in 1992 and Master of Medicine (M.Med, Hons, Slovakia) in 1995 Dr Andrea Rajnakova followed her husband and moved to Singapore.  In 1995 she joined National University Hospital and National University of Singapore as a PhD scholar to begin a Doctorate Medical Studies. She completed PhD thesis on Gastric Cancer in 2000. During the studies she was awarded The Young Doctor's Research Award at NUH Inaugural Annual Scientific Meeting, Singapore, in 1997 and the Best Paper Award for oral presentation at the Nitric Oxide Symposium in Singapore in 1999. In 2009 she was a Winner of Best Oral Presentation (Medical Disciplines) at NHG 8th Annual Scientific Congress 2009.

In 2000 Dr Rajnakova obtained Master of Internal Medicine, Singapore (MMed) and in 2001 the Membership of the Royal Colleges of Physicians of the UK, MRCP. In 2005 she was awarded the Fellowship of the Academy of Singapore in Gastroenterology (FAMS) in 2005.

Dr Rajnakova pursuit her further interest in Therapeutic Endoscopy and ERCP. In 2008 she was awarded a Health Manpower Development Plan (HMDP) by the Ministry of Health, Singapore for further training in ERCP and Therapeutic Endoscopy at European Endoscopic Training Center, Università Cattolica Del Sacro Cuore, Gemelli Hospital, Roma, Italy under Professor Guido Costamagna, President of European Society of Gastrointestinal Endoscopy.

As a Consultant at the Department of Gastroenterology and Hepatology, she practiced at National University Hospital, Singapore until April 2010. She enjoyed teaching of the undergraduate students at  Yong Loo Lin School of Medicine as a clinical tutor and she was appointed as chief coordinator for MRCP PACES in 2009. She was also a mentor and endoscopy trainer for advanced specialists and endoscopy trainees.

For clinical services Dr Rajnakova received several awards: In 2007 Sunny-Side-Up Award NUH Service Award, Sunny-Side-Up Wow Award NUH Service Award and Excellent Service GOLD Award 2007 and in 2008 National Excellent Service EXSA Star Award 2008.

In April 2010 Dr Andrea Rajnakova opened her clinic at Mount Elizabeth Hospital.