On a wintry day, Beth (Keaton) saves a bedraggled lost dog from the side of the freeway. Struggling with her distracted, self-involved husband Joseph (Kline) and an empty nest at home, Beth forms a special bond with the rescued animal. When Joseph loses the dog after a wedding at their vacation home in the Rockies, the distraught Beth enlists the help of the few remaining guests and a mysterious young woman in a frantic search. Each member of the search party is affected by the adventure, which takes them in unexpected directions – comic, harrowing, and sometimes deeply emotional.

Ann Hornaday, Washington Post:
Luckily, "Darling Companion" benefits from some winning performances - not just from Keaton and Kline, who settle in to an easy, unforced rapport, but also from Dianne Wiest and Richard Jenkins (as Joseph's sister and her goofy new boyfriend) and a splendid cameo from Sam Shepard as a crusty town sheriff. (His conversation with Kline comparing PSA counts and bad cholesterol just might be worth the price of admission.)

Lou Lumenick, NY Post:
Sadly, expert work by Kline and other favorite veteran performers such as Diane Keaton, Dianne Wiest, Richard Jenkins and Sam Shepard can do only so much to disguise the narrative impoverishment of this tale of midlife romance among mostly well-to-do 60-somethings.

A.O.Scott, NY Times:
The senior generation is represented by Diane Keaton, Kevin Kline, Dianne Wiest, Richard Jenkins and — in a couple of scenes as a crusty old sheriff — Sam Shepard. How can these people fail to be interesting? The answer is that they can’t, but their collective artistry has the unfortunate effect of exposing the wobbly, threadbare platform that Mr. Kasdan has built for them.

Lael Loewenstein, Variety:
A tale of love lost and redeemed in the wake of a stray dog's adoption, "Darling Companion" arrives with a commendable pedigree. But despite an intriguing premise, a marquee middle-aged cast and a veteran helmer schooled in character-driven ensemble movies, the result is more shaggy-dog story than incisive reflection on human relationships... Production values are fine, in particular Michael McDonough's lensing and Dina Goldman's production design, both of which evoke the best aspects of the Utah locations.

Josef Woodard, Santa Barbara Independent:
It’s a pleasant enough lark of a Kasdan-ian project, but dog people may be dismayed by the fact that the bulk of the screen time is sans dog, which has gone missing in Colorado, a beautiful location in which to have famous actors scramble around in ardent search for said absent pooch. Meanwhile, these searchers’ relationships and human issues are worked out, bandied and candied about.

In short, Kasdan works up some of that old smarmy charm, and calls in some fine thespian voltage — including Kline, Keaton Richard Jenkins, Diane Wiest, and Sam Sheperd — to take on a script which wavers wildly between big warmth and sentimental hokum. When we finally, inevitably catch sight of Casey again, a real modern-day Lassie Moment, we kinda wish this had been more of a true dog picture.

Bruce Ingram, Highland Park News:
Actors of the caliber of Kline and Keaton and Wiest and Jenkins and Shepard are almost guaranteed to find a way to enliven any story, and that’s what happens in “Darling Companion.” Though it’s difficult not to think of better films in which all of them were employed to much, much better effect. Chances are good they could have wrung just as much interest out of a group reading of AARP magazine.