The model looked every inch the yummy mummy at the London-based event, which paid homage to real-life maternity and family heroes.
Imogen - who is mother to one-year-old Ariana Siena - celebrated the surging temperatures hitting the UK right now by opting for a sunny yellow top.
She also sported a ladylike black A-line skirt, which fell just below her knees, paired with a simple pair of round-toe patent heels.
To accessorise her ensemble, Imogen opted for a gold collar necklace and a white watch, plus a classic Chanel 2.55 quilted handbag.
The pretty brunette did up the ante slightly on the beauty front, flaunting smouldering smoky eyes and a bright pink glossy pout.
And while we usually spot Imogen rocking long, tumbling tresses, this time she parted her locks in the middle before slicking back into a low ponytail.
Imogen appeared to be very touched by the awards, tweeting: "I'm here @motherandbaby at Dorchester for the big heart awards. I think it's going to be an emotional day #bigheart."
She later added: "Emotional awards. I'm in bits @MotherAndBaby #BigHearts."
Award categories included 'Mum In A Million', 'Fantastic Father' and 'Brilliant Big Brother or Sister'.
Other attendees at the event included fellow mum Danielle Lloyd - who wore a pretty floral dress for the occasion - and former Atomic Kitten singer Jenny Frost.
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