This study evaluated the use of visualizations in data journalism articles on Mwananchi and The Chanzo websites in Tanzania. The study had three specific objectives: to examine the frequency of journalists’ data visualization usage; to identify the appearance of data visualizations in data-driven articles; and, to uncover the challenges journalists face in using visualizations. The study employed mixed-methods approach. Purposive sampling was used to select 59 respondents from Mwananchi and The Chanzo. The study used questionnaires and content analysis to collect data, which were analyzed using the Statistical Package for the Social Sciences (SPSS). The findings revealed that 34% of journalists rarely used data visualizations; while 25% used them occasionally; 17% used often; 16% never used; and 8% used very often. Among the 52 analyzed articles, 38% included visualizations, with Mwananchi having a slightly higher usage rate (42%) compared to The Chanzo (35%). The Findings means that still there is low usage of visualizations in most of the data articles. The study recommends comprehensive training programs to enhance journalists' data journalism skills, access to advanced visualization tools, and ongoing support to improve data-driven storytelling.