The study was conducted with the purpose of assessing the effectiveness of maize management practices by University-based extension outreach (UBEO) in southwestern Nigeria. 165 outreach beneficiaries were interviewed for the study via structured and pre-tested interview schedule, in the two purposively selected UBEOs using a multistage sampling technique. Data collected were analyzed using descriptive statistical tools such as frequency counts, percentage, mean and standard deviation while inferential statistics such as Chi Square and Pearson Product Moment Correlation were used to test the hypotheses. The mean age of the respondents was 52.4±19.8 and their maize farming experience was 16.4±13.6. Besides, the mean of years in formal education of beneficiaries was 7.4±4.6. Also, 75.6 percent got information about the outreach through their community leaders and they participated to better their lot in life. Many (51.2%) of the respondents have been benefiting for the past 10 years. Besides, maize management practices by UBEOs were appropriate land preparation, seed selection, timely planting and appropriate seed rate among others. The maize yields before and after the management practices were 3.4±1.3 and 4.2±2.1 tons/ hectare respectively, and majority (92.3%) of the maize farmers indicated that the management practices by UBEOs were effective in improving the yield. The findings revealed that at p<0.01, reasons for participation (χ2=31.612) of the respondents had significant association with effectiveness of production technologies. Furthermore, at p<0.01, farming experience (r= 0.503) and years as beneficiaries (r= 0.501) had significant relationship with effectiveness of the management practices; also at p<0.05, age (r=0.322) and years of formal education (r=0.389) of respondents had significant relationship with effectiveness of the management practices. The study concludes that the maize management practices by UBEOs in the study area were effective in improving the capabilities of the beneficiaries. It was recommended that UBEOs be sustained and expanded to cover more rural communities. Keywords: Effectiveness, management practices, university-based extension outreaches