Virunnukari, released on December 10, 1969, was a good social film in Malayalam, but not a success commercially. Its failure at the box office was mainly attributed to the flaws in direction. Produced by Venu and Sreedhar under the banner “Santhasree”, the film was shot at Newton and Prakash Studios. Director Venu himself wrote the script for the story. Dialogues written by P. J. Antony impressed the audience. Cinematography was by Krishnankutty and G. Venkitaraman edited the film.

Popular artistes such as Prem Nazir, K. P. Ummer, P. J. Antony, Adoor Bhasi and Adoor Bhavani acted in the film. The popular heroines of 1960s, Sheela, Ambika and Jayabharathi were included in the cast. The heroine struggling and sacrificing her life for the people she loved, even though they were not related to her was a common formula for Indian cinema in late 1950s and 1960s. Blockbuster Malayalam films like Manavatti (1964) and Adyakiranangal (1964) with similar storylines might have prompted the producers of Virunnukari to follow the formula. Tamil film Kulavilakku (1969) also followed the theme.

Raghava Menon (P. J. Antony), a primary school teacher lives peacefully in a village with his wife Kalyani Amma (Adoor Bhavani) and their children. His son Madhavankutty (Prem Nazir) is an unemployed graduate. Menon’s daughter Malathi (Ambika) is in love with Madhavankutty’s friend Surendran (Ummer). Menon’s younger daughter Santha (Jayabharathi) loves Sethu (Madhu) who is their neighbour and son of a rich landlord. Radha (Sheela), daughter of Menon’s friend gets employed in the village Block Office and she stays with Menon’s family.

Surendran and Radha fall in love at the first sight. With in a short period Radha becomes a member of Menon’s family and becomes the pet of Menon who loves her as his own daughter. When Radha comes to know about Malathi’s love for Surendran, she sacrifices her dreams of a family life with Surendran. She compels and convinces Surendran to marry Malathi and he reluctantly accedes to her request. Menon was staying in a in a rented house owned by Ananthakrishna Iyer (Adoor Bhasi), who wanted him to clear the rent arrears failing which he threatened to proceed against Menon legally. Radha helps Menon pay off the arrears. Radha tried her best to shelter and support Menon’s family. Meanwhile, Menon’s daughter Santha becomes pregnant by Sethu. And he does not come forward to save Santha’s honour. Radha, who hears this, talks to Sethu’s father and even succeeds in conducting Santha’s marriage with Sethu.

Despite her earnest efforts to support and protect Menon’s family, Radha is misunderstood by Malathi and Kalyani. They treat her as their enemy. Malathi was suspicious that Surendran still loved Radha and he could do nothing to clear the misunderstanding. Only Madhavankutty knew Radha’s true love for his family. When humiliation reaches an unbearable level, Radha decides to leave home. She bids good bye to all and leaves Menon’s house. Madhavankutty makes his family understand Radha’s true and selfless love.He consoles Radha and convinces her to come back. The movie ends on a good note with the good-hearted Radha coming back to Menon’s home. Sheela impressed the audience in her pivotal role. In a rather unusual format, the ‘Evergreen Romantic Hero’ of Malayalam Cinema, Prem Nazir, is not paired with a female lead star in this film, though three popular heroines of the time were in the film. P. J. Antony’s natural style of acting was well appreciated.

Songs written by P. Bhaskaran and set to tune by M.S. Baburaj were sung by popular singers. Muttathe Mulla Thann ... (S. Janaki) and Vaasantha sadanathil … (P.Jayachandran) became popular. Other hits from the film include Innale njanoru swapna shalabhamaay… (C. O. Anto, Janaki), Ambadi Pennungalodu … (P. Leela), Pormula kachayumaay … (P. Leela) and Chumalil swapnathin …” (K. J. Yesudas)