About Us

Ratanui Medical has been a group practice in Henderson for over 35 years with a long history of commitment to provide medical care to the community. The practice moved from Ratanui Street to Lincoln Road in 1989 to be in a purpose built building. The three principal doctors are Dr John Caldwell, Dr Chris Wong and Dr Joanna Lang working with other assistant GPs, a GP Registrar and a team of nurses and administration staff.

  • Dr John Caldwell
    John is committed to general practice, having completed his Fellowship in 2014. He encourages an activity, based lifestyle for healthy living and tries to set a good example by cycling, playing tennis in his spare time.
  • Dr Chris Wong
    Chris is a professional teaching fellow with the University of Auckland and teaches medical students. Rather than delivering babies he now performs vasectomies.
  • Dr Joanna Lang
    Joanna is originally trained in Poland and has an interest in woman and child health. She is fluent in Polish and likes the performance arts.
  • Dr Sasha Baijnath
    Sasha is originally from South Africa having immigrated to NZ over 10 years ago. She has many years of GP experience snd is committed to quality patient care. Fashion is one of her keen interests.
  • Dr Cassie Granek
    Cassie is originally from Australia and has now made West Auckland her home. She is interested in travel medicine, Maori and Pacific Island health, and has worked in the past with the indigenous cultures of Australia and East Timor.
    (Currently on maternity leave)
  • Dr Saville Marquis
    Saville is an overseas trained doctor. After becoming registered in NZ, he has worked in Whangarei Hospital and a clinics in West Auckland including Ratanui Medical Centre as a GP Registrar where has returned to Ratanui to work full time. Saville loves sports and in particular cricket.
  • Dr Tila Samuelson
    Tilda trained in Scotland and London and was working in London as a GP prior to moving to New Zealand with her young family. She loves all aspects of GP care.
  • Dr Abigall Smith (Abby)
    Abby is from Northland and trained at Auckland Medical School. She works part-time as she has two preschool aged children. She has a particular interest in Women's Health and Paediatrics. Abby works Thursdays and Fridays and shares the practice with Dr Tilda Samuelson.