As the police disperse a group of elderly citizens demanding a long-overdue pension increase, Umberto D. Ferrari (Carlo Battisti), a retired government worker, returns to his modest apartment only to discover it has been taken over by a youthful couple indulging in a brief moment of intimacy. His landlady's harsh decision to rent the space has left him with a daunting dilemma: he must pay the overdue rent of 15,000 lire within just two weeks. Time is not on his side; in a desperate bid to gather funds, Umberto parts with his cherished watch and books, but the little money he manages to raise is barely sufficient to make a dent in his troubles.
In the midst of this turmoil, the compassionate maid reveals her own difficulties to Umberto. She finds herself emotionally torn between two soldiers vying for her affection, with the added anxiety of uncertainty surrounding which of them could be the father of her three-month-old child.
As Umberto's health begins to fail, he finds solace in a hospital, where he is diagnosed with tonsillitis. After a few days of rest, he is discharged, but upon returning home, he finds his apartment in disarray with workmen expanding the living room space. The news of his landlady's upcoming marriage serves as a painful reminder of his own financial struggles.
The maid shares heartbreaking news that Flike, Umberto’s cherished dog, has gone missing, deepening his despair. Anxious to protect his best friend, Umberto rushes to the city pound and is overjoyed to find Flike safe and sound. However, when he turns to a friend for financial help, his request falls on deaf ears, intensifying his sense of isolation and hopelessness.
Faced with overwhelming despair, Umberto contemplates a tragic end, yet the thought of leaving Flike unprotected stops him in his tracks. Gathering his belongings, he prepares to leave the apartment, imparting a final piece of wisdom to the maid: to cut ties with the unsuitable suitor from Florence.
As Umberto’s desperation escalates, he embarks on a fruitless search for a permanent home for Flike, initially approaching a couple who love dogs and then a young acquaintance. However, a strict nanny intervenes, forcing a little girl to surrender her newfound companion, and Umberto is left feeling defeated, unable to help his beloved dog find a stable future. With a heavy heart, he secretly slips away from Flike's playful moments with new friends, clinging to the hope that someone may take pity on the dog.
Meanwhile, Umberto himself fades into the shadows, but Flike’s loyalty prevails as he locates his owner, tracking him down to a footbridge where Umberto hides, weighed down by sadness. In an act of desperation, Umberto gathers Flike in his arms and heads toward the nearby railway tracks, unaware of the danger that looms.
As the train approaches, Flike’s instincts kick in; the dog wriggles free from Umberto’s grasp and dashes away, prompting Umberto to chase after him. Initially cautious, Flike hides in fear, but as Umberto calls him over with a pine cone, their bond is rekindled through play.
Despite lacking a permanent home, Umberto and Flike forge an unbreakable connection as they navigate the challenges of life on the streets. Each day that passes strengthens their bond, a profound testament to the lasting power of friendship amidst adversity.
