Charitable organizations play a significant role in today's society that cannot be achieved by governments or businesses. They have missions ranging from providing hot soup to victims after an earthquake to providing shelters to refugees running away from the war. However, in order to achieve these missions, they need the support of individuals in terms of monetary and time donations (voluntary work). Charitable organizations act as intermediaries and they transmit the sources from the wealthy people who want to help the needy. The importance of individual giving for charitable organizations attracted the research in the marketing field and authors examined the role of attitudes and perceptions. A range of attitudinal and perceptual factors can influence individuals' charitable giving intention including attitudes toward charitable organizations, attitudes toward helping others, and trust in the third sector. The prior studies have demonstrated that these variables were interrelated. However, they examined the relationship between these variables and charitable giving intention independently and it is still unclear how these perceptual and attitudinal variables are associated with each other and charitable giving intention. To fill this research gap, the purpose of this study is to test the serial mediating role of attitudes toward charitable organizations and trust in the third sector in the relationship between attitudes toward helping others and charitable giving intention. We, therefore, built a serial mediation model showing the relationship between the variables and tested it with the data obtained from a convenience sample of 417 respondents who live in the Eastern Marmara Region, Turkey. Our findings show that attitudes toward helping others have a positive indirect effect on both intended to give time and intention to give money through attitudes toward charitable organizations and trust in the third sector in sequence. Additionally, attitudes toward charitable organizations have a positive specific indirect effect on the intention to give time and intention to give money in sequence through trust in the third sector. Also, trust in the third sector has a positive direct effect on the intention to give time and intention to give money. These findings indicate that attitudes toward charitable organizations and trust in the third sector sequentially mediate the relationship between intention to give time and intention to give money. The results also suggest that the proposed model explains almost 35% of the variance in intention to give money and 11% of the variance in intention to time.