• Emergency Case

    Emergency & Life-Threatening Issues Please Call 911, For After Hours / Urgent Messages Please call 702-202-2233
  • Services

    At Mountainside Internal Medicine, we treat a variety of conditions and ailments. Please take a look at all of our services.
  • Opening Hours

    • Monday - Friday
      8:00 am - 5:00 pm
    • Saturday (By Appointment)
      10:00 am - 1:00 pm
    Bilinqual- Spanish speaking services available


Dr. Osei is one of my favorite doctors! He is not just a good listener but also a very caring doctor. Nowadays it is not easy to find a doctor that actually listens to what their patient has to say. Dr. Osei is very professional and I would recommend him to all of my families and friends.

Marlene C., Yelp Review, March 21st , 2018

Very caring Doctor, recommend to all my family and friends.

Sara, HealthGrades Review, July 25th, 2018

One of the best doctors I have ever had. Great bedside manners and takes his time with his patients!

Jorge R., Yelp Review, October 31st , 2018

I just moved from California and was looking for a PCP and Mountainside Internal Medicine was able to get me an appointment as soon as possible. The staff and doctor are great and I would totally recommend this doctor!

Jennifer, HealthGrades Review, August 15th, 2018

We moved from Washington State to Nevada 9 months ago. Looking for a PCC is challenging sometimes! Dr. Osei and his staff made our transition very easy. Very caring, attentive and knowledgeable! I would highly recommend this office, we feel very comfortable here!

Tamara W., Yelp Review, June 28th, 2018

Wouldn’t go anywhere else! Dr. O is very knowledgeable and up to date! A tad bit on the quiet side but knows his stuff! As for his staff….?? They are great! Makes every visit easy and accommodates your every need! Very rare find these days!

Mz Chuthee, HealthGrades Review, October 23rd, 2018

Dr. Osei, we had nothing but outstanding medical treatment from you and great support from your staff. We are fortunate that Dr. Manalo referred us to you after she left Las Vegas. Thank you very much. May you have your loved ones have a Happy Thanksgiving and we wish you continued success in your practice.

Edgardo V. – November 25th, 2014

Edgardo L. Vicedo

Dear Dr. & Mrs. Osei, Stacy and I are very grateful for your warm and precise care, not only for our physical health matters but also for our piece of mind. Because of my advanced stage in life at this time I am much more at peace for you are there for Stacy. Thank you! I am also indebted to you for making it possible to be in your care in the coming year. All of the fabulous and peace be with you in the abundant blessings of our lord. Happy New Year to you, your loved ones and your staff. Respectfully…..

J. Grace Y. – Decemeber 13th, 2013

J. Grace Yoon

Dr. Osei and staff, words cannot express how extremely surprised and touched I was for the beautiful, stunning floral arrangement you sent. That was seriously the most thoughtful thing I have ever experienced. The fact that you cared about me, and my recovery made me realize how extremely lucky and cared for YOUR patients are! With great appreciation….

Tina N. (Tera’s sister)

Tina Nowan (Tera’s sister)

Your comforting expression of sympathy will always be remembered with deep gratitude.

Maribel G – April 8th, 2016

Maribel Garcia

Meet Dr. Henry Osei

Dr. Henry Osei is Board Certified in Internal Medicine. He specializes in providing internal medicine services and primary health services to the community. Dr. Henry Osei practiced with Southwest Medical Associates(Sierra Health) for 6 years here in Las Vegas. Before his move to Las Vegas, Dr. Henry Osei practiced with Kaiser Permanente for 7 years in the east coast, in the Maryland/DC area.

He completed his residency at Sinai Hospital, an affiliate of John Hopkins University Medical School in 1992 in Maryland. He has been in practice over 15 years.

Dr. Osei is board certified in Internal Medicine and cares for adult patients from ages 18 and older. Dr. Osei manages diseases such as diabetes, hypertension, lung diseases, heart diseases, kidney diseases and many other adult related diseases. He also does physicals. Dr. Henry Osei is compassionate and takes quality patient care to heart.

In his spare time, Dr Osei enjoys tennis, jazz music and reading.

Our Services

For your convenience, we offer many services, including: