Studies on self-determination theory (SDT) have placed satisfaction of basic psychological needs (autonomy, relatedness, and competence) at the core of well-being, whereas frustration of these needs results in multiple potentially unhealthy mental and behavioral patterns. This study analyzed how need satisfaction and frustration relate to the severity of gambling and gaming problems.A survey study with 18-75-year-old Finnish participants (N = 1530; 50.33% male) was conducted in April 2021. Basic psychological needs were measured with the Basic Psychological Need Satisfaction and Frustration Scale, mental health issues with the five-item Mental Health Inventory, gambling problems with the Problem Gambling Severity Index, and gaming problems with the Internet Gaming Disorder Test. Zero-inflated negative binomial analyses were conducted to examine how satisfaction and frustration of basic psychological needs, together with mental health issues, are associated with gaming and gambling problems.Mental health issues were associated with gambling and gaming problems, but this association became nonsignificant when basic psychological needs were added to the model. However, better mental health still was associated with the absence of gaming problems. While need satisfaction had no association with the absence of gaming or gambling problems, need frustration was associated with increases in the severity of both gaming and gambling problems.Frustration of basic psychological needs for autonomy, relatedness, and competence is associated with both gambling and gaming problems and should be considered when developing treatment and support for those who experience such problems.