Can a horse/filly race in a Stakes Race if it hasn't won a maiden race yet?

Yes. A Maiden race is a Race where all entrants have never won a race. A Horse can at anytime be entered into a Race as long as he meets the entrant fee or other criteria.

I may be wrong but this is my thoughts

Unless the stakes has some requirement to enter, then any horse can run, regardless of if they won before. For example, a maiden wouldn't be able to run in the Kentucky Derby because it would not have enough earnings to get in. Nor would a maiden be able to get into the Breeders Cup. However, in ordinary stakes, it's not uncommon for trainers to enter a horse who has not broken its maiden because the purse is so much higher, so they're willing to take the risk. It's maybe not as common in graded stakes, but it's really common in ungraded stakes at low level tracks, especially for 2 year olds in the fall because most of the 2 year olds are just starting out. I've seen unraced horses enter their first race in a statebred stakes. You don't see it a lot with older horses, but with 2 year olds, it's a pretty level playing field... none of them have had any experience, so you can't really tell who's the best until they have all run in a few stakes.

If you remember the 2008 Belmont, the horse breaking from post 2 was a horse named Guadalcanal and he was still a maiden... they thought they'd take a shot at the 1 1/2 on dirt... and the horse did manage to beat Big Brown!! lol

You can enter a maiden in any race you want but I prefer that they enter a maiden race until they win and then go into non-winners of 2. Once a maiden won the Kentucky Derby and then won the Triple Crown. A filly or mare can run against the colts and geldings if it wants to but I would not recommended it because they have similar races.

Absolutely a maiden can run in a stakes race. And can win!

To cite just one example, on the 20th of September, Stormy Ballad, a maiden 3-year-old, won the $100,000 Lake Michigan Stakes. http://www.ntra.com/content.aspx?type=news&id=3497...

In 2000, the maiden Scatter the Gold won Canada's Queen's Plate, one of the Canadian Triple Crown races: http://www.thoroughbredtimes.com/national-news/200...

On the 28th of September, on the Breeder's Cup "preview weekend" at Santa Anita's Oak Tree meet, Street Hero broke his maiden in the Group I Norfolk stakes. http://articles.tracksideview.com/2008/09/28/stree...

There are no rules about the entry of maidens in stakes races. Most horses "run through their Conditions" before going into stakes-- Maiden Special Weights, Non-winners other than Maiden, Non-winners of two other than, etc., simply because that's the track in which they are competitive. Since racing is all about winning, there isn't much point in running at a level in which a horse isn't competitive.

While it's unlikely, since the Breeder's Cup races are usually oversubscribed and they have to limit the field, it is possible for a maiden to run in the Breeder's Cup.

...And in a final salute to maidens, let's never forget that the first Triple Crown winner, Sir Barton, was a maiden when he won the Kentucky Derby in 1919!

i guess it depends on what country, maybe some are different!

in australia, there was a horse named moatize....... he hadn't won any races but was racing in group races, and being competative too!

also a fillie named love and kisses..... currently a maiden but racing in black type races, she is also very competative.

yes