Aim: Intracanal posts enhance the resistance of the restoration to mechanical loads and masticatory forces in primary teeth with extensive carious breakdown. This study was done to investigate the clinical performance of composite resin restoration retained by either glass fiber post or biological post in the restoration of primary anterior teeth with extensive carious lesions. Materials and methods: A total of 21 children (with 82 primary anterior teeth) who met the inclusion criteria were involved in the study. The 82 primary maxillary incisors were randomly allocated into two equal groups: groups I (glass fiber post) and II (biological post). All the teeth underwent pulpectomy, followed by glass fiber post or biological post, followed by celluloid strip crown restoration. Clinical analysis of all the teeth in the two groups was performed at 1, 3, 6, 9, and 12 months to assess the success of treatment procedures. Statistical Package for the Social Sciences (SPSS) software version “17” was used for statistical analysis. Pearson's Chi-squared test and Fisher's exact test were utilized to evaluate the success of both treatment procedures. The significance level was predetermined at p < 0.05. Results: At the end of the 12-month follow-up period, 89.4 and 84.2% of composite resin restorations of primary incisors with extensive carious lesions were retained by glass fiber and biological posts, respectively. The intergroup comparison revealed no statistically significant differences pertaining to retention loss, marginal discoloration, and marginal adaptation at all follow-up intervals (p > 0.05). Conclusion and clinical significance: Since biological posts are inexpensive and economical, they may replace the commercial post systems available to pediatric dentists.