Yes, I think that they preferred to keep him a bachelor.
~~
JimHutton (1934-79) and ElleryQueen

I found the wickapedia page that talks about Ellery's background there is a little more info about his mother, but not how she died.
It also says that Ellery was married and a father in the first couple of novels (I guess the mystery portion was a flashback) but the storyline was dropped.
http://en.wikipedia.org/wiki/Ellery_Queen
How sad, that you were not born in my time, nor I, in yours.

We never know in the books what happens to Ellery's mother although there are a few hints about him having been young when she died. Inspector Queen's Own Case is a great story by the way, if you can track it down.
It is not our abilities that show who we truly areit is our choices

exactly- miss Mr. Hutton- e sreies- which lead me to the books- love themgave my dad and I somehing incommon- in my mid teen years always a good thing=!!!
Hmm well, you're having the best of the argument so far. Patrick Harper

I don't think it's ever explained in the series. However, in the novel "Inspector Queen's Own Case", we are told that Richard Queen has been a widower for years and years. He finds romance in that novel, by the way.
Ellery Queen (Jim Hutton) = sexiest man ever!

One of these days, I should reread "The Roman Hat Mystery" (the first Ellery Queen mystery). In that book, it probably says what happened to Ellery's mother.
Ellery Queen (Jim Hutton) = sexiest man ever!

Remembering this show took place in the 40's, really it could have been anything - cancer, childbirth, car accident (I am not sure cars had all the safety features they have now, back then),
Boy, where to start on this one?
No air bags or antilock brakes just the tip of the iceberg. How about dashboards made of solid, heavy-gauge metal? No seat belts. Rigid steering columns and steering wheels. No "crumple zones". No power brakes or power steering. Much dimmer headlights. (I could go on, but you get the idea.)

I've seen all the eps numerous times, and no- they never said. I don't think they ever said in detail in the novels either. (unless maybe it is in Inspector Queen's Own Case one of the novels. I haven't read it in years).
Remembering this show took place in the 40's, really it could have been anything - cancer, childbirth, car accident (I am not sure cars had all the safety features they have now, back then) TB.. the only thing I am pretty sure of is she wasn't murdered!
Many times, when you set up a situation where there is a widow or widower involved, they just say the spouse died, and leave it to the reader's/ audience's imagination as to what happened examples I can think of off the top of my head, Carolyn Muir - widow in The Ghost and Mrs. Muir, Carol Williams Brady in the Brady Bunch, Mike Brady, in the Brady Bunch, Doris Day on the Doris Day Show and Shirley Partridge in the Partridge Family. All these shows had spouses who died, but none of them are specific as to how. I am sure there are more modern shows too - the shows I am talking about are all late 60's to 1970 - which is not that long before EQ.

I'm watching the episodes in broadcast order, beginning with the pilot. Last night I watched "The Adventure of the Chinese Dog" and so far, nothing has been said about Ellery's mother in any of the episodes I've seen. I'll keep watching.
It's such a great show though, isn't it???
Cheers!