Sérgio Miguel Garcia Vieira (born 20 February 1976) is a Portuguese race walker. His twin brother, João Vieira, is also a race walker.[1]
| Year | Competition | Venue | Position | Event | Notes |
Representing  Portugal |
| 1994 |
World Junior Championships |
Lisbon, Portugal |
22nd |
10,000 m |
43:50.07 |
| 1997 |
World Race Walking Cup |
Poděbrady, Czech Republic |
26th |
20 km |
1:20:58 |
| European U23 Championships |
Turku, Finland |
— |
20 km |
DNF |
| 1999 |
World Race Walking Cup |
Mézidon-Canon, France |
41st |
20 km |
1:28:08 |
| 2006 |
World Race Walking Cup |
A Coruña, Spain |
45th |
20 km |
1:26:22 |
| 2007 |
World Championships |
Osaka, Japan |
— |
20 km |
DNF |
| 2008 |
World Race Walking Cup |
Cheboksary, Russia |
18th |
20 km |
1:21:25 |
| Olympic Games |
Beijing, China |
45th |
20 km |
1:29:51 |
| 2009 |
European Race Walking Cup |
Metz, France |
— |
20 km |
DNF |
| World Championships |
Berlin, Germany |
27th |
20 km |
1:24:32 |
| 2010 |
European Championships |
Barcelona, Spain |
20th |
20 km |
1:27:07 |
| World Race Walking Cup |
Chihuahua, Mexico |
25th |
20 km |
1:27:25 |
| 2011 |
European Race Walking Cup |
Olhão, Portugal |
— |
20 km |
DNF |
| 2012 |
World Race Walking Cup |
Saransk, Russia |
— |
20 km |
DNF |
| 2013 |
European Race Walking Cup |
Dudince, Slovakia |
29th |
20 km |
1:27:14 |
| World Championships |
Moscow, Russia |
40th |
20 km |
1:28:34 |
| 2014 |
World Race Walking Cup |
Taicang, China |
60th |
20 km |
1:24:13 |
| 2015 |
European Race Walking Cup |
Murcia, Spain |
— |
20 km |
DNF |
| World Championships |
Beijing, China |
— |
20 km |
DNF |
