This study evaluated the effects of affective intensity and thematic content of foreground photographic stimuli on various physiological response systems. This was accomplished by assessing responses to pictures that varied systematically in these parameters. Along with overall effects of picture valence reported in previous work, we found effects of thematic content (i.e., specific nature of objects/events depicted) for all measures except heart rate. In addition, we found that the magnitude of startle blink, skin conductance, and corrugator muscle reactions increased with increasing affective intensity of pictures. Additionally, for these three measures, intensity effects also interacted with effects of picture content. These results indicate that stimulus parameters of intensity and thematic content exert separate—and in some cases interactive—modulatory effects on physiological reactions to emotional pictures.