The plot revolves around Neeli, a Dalit peasant girl, who falls in love with Sreedharan Nair, a high caste teacher.

The script was praised for its hard-hitting dialogues against social evils such as untouchability, feudalism and injustices towards women.The performance of the cast, who spoke in the regional dialect was also critically acclaimed.

[4] There are nine songs, scored by K. Raghavan and penned by P. Bhaskaran, in a soundtrack regarded as a milestone in Malayalam film music history.

The popular songs from the film are "Ellarum Chollanu Ellarum Chollanu" Janamma David, "Kayalarikaathu Vala Erinjappol" (K. Raghavan), "Unarunaroo Unnikanna" (Shantha P. Nair), "Kadalasu Vanchi Eri" (Kozhikode Pushpa) (Based on the Tyagaraja composition in Kapi Narayani) "Sarasa Sama Daana Bheda"), "Maanennum Vilikkilla" (Mehboob), "Kuyiline Thedi" (Janamma David) and "Engane Nee Marakkum Kuyile" (Kozhikode Abdul Kader).

The song "Kayalarikaathu Vala Erinjappol" was used in Deepan Sivaraman's stage adaptation of O V Vijayan's magnum opus, Khasakkinte Itihasam.

He concludes writing "Though Moithu’s character does not fit into the narrative scheme, the role was essayed excellently by Balakrishna Menon.”[9] Film historian, Jenson Joseph said, "If Social Realism in Indian cinema meant melodramatic rendering of the issues of the poor and the oppressed, Neelakuyil fits perfectly into this genre.

Neelakuyil was the first Malayalam film to come to grips with social realism and was a protest movie, the likes of which had not been attempted before with such depth and commitment.

"[13] Rajadhyaksha and Willemen, in Encyclopedia of Indian Cinema, wrote, " The trend of realist melodrama inaugurated by this film was to continue for over 20 years, in Kariat’s own work and e.g. in Vincent’s M.T.