This study examined the factors that advertising practitioners in Nigeria consider when selecting media for advertising campaigns. The survey research method was applied to collect data with the structured questionnaire as the research instrument. 120 copies of the questionnaire were administered on the respondents who were members of the Media Independents Association of Nigeria (MIPAN) sectoral group of the Nigerian advertising industry. The purposive sampling technique was employed for selecting respondents in order to eliminate waste. 110 copies of the questionnaire were properly completed and returned representing 91.6 percent response rate. Findings revealed that reach was the most important factor that influenced media selection among advertising practitioners in Nigeria as indicated by 40.5 percent of the respondents. This was followed by cost of media as well as available budget for advertising campaigns. Other factors include prestige, image, rating and share of media as well as circulation with respect to the print media. Radio emerged as the most preferred advertising medium as indicated by 37 percent of the respondents. It was followed by newspaper, television and online media respectively. The major conclusion drawn from this study is that traditional media of mass communication are still the preferred advertising media among advertising practitioners in Nigeria. It was recommended that private media owners should increase the reach of their media outlets in order to attract more advertising revenue. It was further recommended that future researchers should investigate how Nigerian advertising practitioners determine some of the variables utilized in media selection. These include reach, prestige, image, and share of advertising media. Furthermore, it was recommended that constant research be conducted to determine the actual reach of media outlets in Nigeria as opposed to unsubstantiated claims by media owners.