The present invention relates to a Lactuca sativa seed designated 41-191 RZ, which exhibits a combination of traits including resistance to downy mildew (Bremia lactucae) races Bl:1 to Bl:32 and CA-I to CA-VIII, resistance to currant-lettuce aphid (Nasonovia ribisnigri) biotype Nr:0, as well as having a hollow main vein, broad base leaves, a small head size and a small plant size. The present invention also relates to a Lactuca sativa plant produced by growing the 41-191 RZ seed. The invention further relates to methods for producing the lettuce cultivar, represented by lettuce variety 41-191 RZ.